LIBRARY 

UNIVERSITY  OF 

CALIFORNIA 
SANTA  CRUZ 


UNIVERSITY  OF  CALIFORNIA. 


FROM   THI-    LIBRARY    (  )l 


BENJAMIN  PARKE  AVERY. 


GIFT  OF  MRS.  AVERY. 

August,  1806. 

Accessions  No.  Class  No. 


Universy  o 
^General    Library 


./• 


METEORS, 

/ 


AEROLITES,  STORMS,  AND  ATMOSPHERIC 
PHENOMENA. 


FROM  THE   FRENCH   OF 

ZUECHEK  AND  MAEGOLLE. 


BY 

WILLIAMLACKLAND. 


, 

ILLUSTRATED   WfTff  TWENTY-THREE  FINE   TTOOMffTS,  BY  LEBRETON. 


NEW  YORK: 

D.    APPLETON    AND    COMPANY, 

90,  92  &  94  GRAND  STREET. 

1870. 


ENTBKED,  according  to  act  of  Congress,  in  the  year  1869,  by 

D.  APPLETON  &  CO., 

in  the  Clerk's  Office  of  the  District  Court  of  the  United  States  for  the 
Southern  District  of  New  York. 


PREFACE. 


THE  nations  of  antiquity  contemplated  the 
grand  spectacles  that  Nature  offers  with  emotions 
different  from  ours.  Their  admiration  partook 
more  largely  of  amazement  and  fear. 

We  read  in  the  Vedas,  or  sacred  books  of 
India,  the  following  sentences  : 

"  Will  the  sun  rise  again  ? 

"  Will  our  beloved  aurora  return  ? 

"  Will  the  powers  of  the  night  be  conquered 
by  the  god  of  day  ? " 

To  us  these  questions  seem  strange.  Were 
they  put  in  earnest  ?  Were  the  men  of  the  ear- 
liest ages  serious  when  they  asked  themselves  anx- 
iously at  night  whether  the  light  of  day  would 
overcome  the  darkness,  and  reappear  at  dawn  to 
restore  sunshine,  heat,  and  life,  to  the  world  ? 


4:  PREFACE. 

Yes,  there  is  no  doubt  of  it ;  history  attests  the 
fact ;  the  earliest  nations  thought  that  the  stars 
were  animated,  living  bodies.  In  their  eyes  the 
heavenly  bodies  were  superior  beings,  good  or 
bad  deities,  friends  or  enemies,  and  ever  ready  to 
engage  in  conflicts  of  which  the  issue  might  be 
favorable  or  injurious  to  mortals. 

The  Aurora,  or  Dawn,  itself  was  one  of  these 
divinities,  and  the  most  charming  of  them.  Al- 
ways beautiful  with  freshness  and  youth,  she  was 
ever  saluted  and  hailed  with  gratitude,  because 
she  it  was  who  came  the  first  to  announce  the  de- 
feat of  the  powers  of  darkness  and  evil,  and  each 

+ 

morning,  like  a  tender   and  faithful  messenger, 
awoke  the  sons  of  men. 

It  is  not  with  these  childlike  feelings  that  we 
moderns  contemplate  the  sublime  scenery  of  cre- 
ation. "We  never  entertain  a  doubt  in  our  day 
of  the  regular  reappearance  of  the  sun ;  we  know 
beforehand  the  hour,  the  minute,  nay,  the  very 
second  of  his  rising,  and  we  can  calculate  with 
precision  the  length  of  the  dawn  in  different 
climes.  But  this  happy  certainty,  which  we  owe 
to  science  and  experience,  has  not  weakened  the 


PREFACE.  5 

sense  of  admiration  in  our  souls.  On  the  con- 
trary, this  religious  and  prolific  feeling  has  in- 
creased in  strength,  in  elevation,  and  has  become 
more  and  more  chastened  as  reflection  and  study 
have  gradually  revealed  to  us,  with  greater  force 
of  testimony,  the  infinite  power  and  goodness  of 
the^Great  Being  who  presides  over  the  universe. 
"We  follow  with  an  interest  full  of  poetic  thought 
the  progress  of  the  human  mind  in  the  study  of 
these  natural  forces,  these  material  agents,  these 
vast  springs  of  life  and  motion,  that  obey  the  will 
of  God,  and  of  which  the  ancients  had  only  so 
confused  an  idea.  How  vast  a  field  is  here 
opened  to  observation,  even  when  limited  to  the 
phenomena  which  have  merely  the  terrestrial  at- 
mosphere for  their  theatre  !  What  a  variety  of 
effects  are  produced  around  us  by  the  action,  and 
by  the  incessant  combinations,  of  the  three  ele- 
ments—  air,  fire,  and  water* — which  serve  to 
maintain  and  develop  life  in  all  its  grades  and 
in  all  its  forms  on  the  surface  of  the  globe  ! 

It  has  been  said  with  truth  by  Ernest  Faivre, 

*  Atmospheric  phenomena  are  usually  divided   into  aerial, 
aqueous,  or  igneous  meteors. 


6  PREFACE. 

in  his  book  entitled  "  The  Scientific  Works  of 
Goethe : "  "  The  spectacle  of  the  various  condi- 
tions of  the  sky ;  the  changing  aspects  of  the 
clouds,  the  rain,  the  hail,  and  the  tempest,  as 
they  form  above  our  heads ;  the  appearance  of 
luminous  meteors,  such  as  the  aurora  borealis, 
the  halo,  and  the  rainbow,  have  in  them  some- 
thing marvellous  that  enchains  attention ;  and 
for  an  intelligence  capable  of  deep  appreciation 
such  studies  must  have  a  resistless  charm." 


CONTENTS. 


CHAPTER  I. 

THE  ILLUMINATION   OF   THE   ATMOSPHERE. — TWILIGHT. — THE   MIBAGE. 

The  Atmosphere.— The  Azure  Vault  of  the  Sky.— The  Prolongation  of 
Daylight.— Colors  of  the  Spectrum.— Twilight  in  the  Polar  Regions.— 
The  Anti-Twilight.— The  Mirage.— The  Fata  Morgana 13 

CHAPTER  H. 

OLOTJDS     AND     FOGS. 

The  Clouds.— Formation  of  the  Clouds  and  Mists.— Influence  of  the  Ma- 
rine Currents. — Extraordinary  Fogs. — Appearance  and  Motion  of  the 
Clouds.— Hail-Clouds.— Forms  of  the  Clouds.— Cloud-Rings.— Influ- 
ence of  the  Mountains.— Distribution  of  the  Clouds.— The  Spectre  of 
the  Brocken.— The  Shadow  of  Mont  Blanc...  ..  84 


CHAPTER  III. 

BAIN,    SNOW,    AND    HAIL. 

Dew.— White  Frost.— The  Distribution  of  Rain  on  the  Surface  of  the 
Globe.— The  Great  Rains  of  India.— Regions  without  Rain.— Influ- 
ence of  Forests.— The  Softening  of  Climates.— Forms  of  the  Snow.— 
Flowers  under  the  Snow.— Glaciers  and  Rivers.— Hail 61 


CONTENTS. 


CHAPTER  IV. 

PHENOMENA   OF  THE   GLAOIEES. 

Meteorology  of  the  Glaciers.— Their  Formation.— The  Grindelwald  and 
Furca  Glaciers.  —  Amphitheatres. — Neves. — Moraines. — Movements 
of  the  Glaciers.— Primitive  Glaciers.— Polar  Glaciers.— Variations  of 
the  Seasons  and  Climate ...  . .  86 


CHAPTER  V. 

THUNDER- STOKMS. 

Lnminons  Phenomena.— The  Fires  of  St.  Elmo.— Thunder-storms  among 
the  Mountains.— The  Forms  of  Lightning.— Globular  Thunder- bolts.— 
Thunder.— Singular  Effects  of  Lightning.— Lightning-rods.— Geogra- 
phy of  Thunder-storms.— Influence  of  the  Soil.— Volcanic  Storms.— 
Action  of  Thunder-storms  upon  the  Subterranean  Waters.— Utility 
of  Thunder-storms 104 


CHAPTER  VI. 

WHIRLWINDS. 

Water-spouts.— Electric  Whirlwinds.— Sand-storms.— Water-spouts  at 
Sea.  —  Water-spouts  on  Land.  —  Tornadoes.  —  Cyclones.  —  Hurri- 
canes... ..  139 


CHAPTER  VII. 

RAINBOWS. — CROWNS,   AND   HALO8. 

Description  of  the  Rainbow.—Play  of  Light  in  the  Drops  of  Water.— 
Varied  Appearances  of  the  Arch.— Supplementary  Arcs.— The  Cir- 
cles of  Ulloa.— Crowns.— Colored  Arcs.— Parhelia.— White  Arcs.— 
Anthelia.— The  Halo  of  Clere . . .  . .  170 


CONTENTS.  1J 

CHAPTER  VIII. 

THE    ATTBOBAL    LIGHTS. 

General  Description.— Icy  Fog.— Noise  and  Odor.— Electrical  Currents. 
—Magnetic  Influence.— The  Aurora  Australia.— Different  Points  of 
View.— Periodicity  of  the  Auroral  Lights 190 


CHAPTER  IX. 

SHOOTING-STABS. 

Fire-balls.— Showers  of  Stones.— Meteoric  Stones.— An  Extraordinary 
Meteor.— Velocity  and  Appearance  of  Fire-balls.— The  Fall  of  Aero- 
lites.— Periodical  Reappearances. — Composition  of  Aerolites. — Dark- 
ening of  the  Sun.— Ring  of  Meteorites 207 


CHAPTER  X. 

DUST  IN  THE  ATMOSPHEBE. — DBY  TOGS. 

Cosmic  Dust.— Volcanic  Ashes.— The  Sands  of  the  Deserts.— The  Red 
Mists  of  Cape  Verde.— Showers  of  Manure.— Dry  Fogs 235 


CHAPTER  XI. 

PBOGNOSTICS  OF  THE  WEATHEB. 

Progress  of  Meteorology.  —  Foretelling  the  Weather.  —  Orpheus,  Ho- 
mer, Hesiod,  Virgil.— Prognostics  furnished  by  Animals.— Prognos- 
tics from  Plants,  and  from  the  State  of  the  Sky.— Characters  of  the 
Seasons  and  of  Future  Years.— Shooting-Stars.— Influence  of  the 
Moon 261 

CHAPTER  XII. 

PBAOTIOAL  METEOBOLOGY. 

The  Brussels  Conference.— Meteorological  Practice.— Instruments  of 
Observation.— Telegraphic  Meteorology.— The  Hurricane  of  Decem- 


10  CONTENTS. 

ber  2,  1863. — Alarm-Signals. — Rural  Meteorology. — Association  for 
the  Advancement  of  Meteorology 286 

NOTES. 

IN8TBTTHENT8  OF  OBSERVATION. 

The  Barometer.— The  Thermometer.— The  Hygrometer.— The  Pluvi- 
ometer or  Udometer 319 


LIST  OF  ILLUSTRATIONS. 


PAGB 

THE  MIBAGE, 25 

FATA  MOBGANA, 30 

CIEEUS  AND  STEATUS, 48 

NIMBUS  AND  CUMULUS, 49 

SPEOTEE  OF  THE  BBOOKEN, 55 

SHAPES  OF  SNOW-FLAKES, 77 

THE  LYSE-FIOED, 131 

A  VOLCANIC  STOEM, 133 

A  WATEB-SPOUT, 148 

A  HUEEIOANE, 163 

A  RAINBOW, 170 

WATEEFALL  KAINBOWS,    .  173 

THE  OIECLE  OF  ULLOA, 178 

HALOS, 182 

THE  AUEOEA  BOEEALIS, 190 

THE  HUEWOETH  METEOB, 214 

SHOWEE  OF  SHOOTING-STABS, 227 

A  WILL-O'-THE-WISP, 255 

THE  STOEM-GLASS, 294 

ALAEM-SIGNALS, 306 

THE  PLUVIOMETEB, 323 


METEOBS   AND    METEOEIO 
PHENOMENA. 


CHAPTEE  I. 

THE  ILLUMINATION  OF  THE  ATMOSPHERE.— 
TWILIGHT.— THE  MIRAGE. 

The  Atmosphere.— The  Azure  Vault  of  the  Sky.— The  Prolongation  of 
Daylight.— Colors  of  the  Spectrum.— Twilight  in  the  Polar  Regions. — 
The  Anti-Twilight.— The  Mirage.— The  Fata  Morgana. 

THE   ATMOSPHERE. 

"  THE  atmosphere  surrounds  the  earth  with  a 
spherical  envelope,  or  wrapping,  the  thickness  of 
which  is  unknown.1 

"  However,  numerous  observations  have  indi- 
cated that  the  limit  of  this  atmospheric  envelope 
cannot  be  either  less  or  more  than  a  little  over 
sixty-two  miles. 

"  This  atmosphere,  although  invisible,  presses 
on  the  surface  of  our  bodies  at  the  rate  of  fifteen 

1  It  will  always  be  impossible,  perhaps,  to  attain  a  rigorously 
accurate  estimate,  because  the  rarefaction  of  the  upper  layers 
augments  precisely  as  the  height  is  greater  and  the  pressure  less. 


14  METEORS   AND  METEORIC   PHENOMENA. 

pounds  per  square  inch,  so  that  each  of  us  carries 
about,  without  feeling  it,  a  total  weight  of  nearly 
35,000  pounds. 

"  Lighter  than  the  lightest  down,  less  palpable 
than  the  most  delicate  filaments,  it  leaves  intact 
the  spider's  web,  and  hardly  bends  upon  their 
stalks  the  flowers  that  it  refreshes  with  its  dews  ; 
yet  it  bears  with  it  around  the  world  the  ships  of 
all  nations  on  its  wings,  and  crushes  the  hardest 
rock  or  metal  with  its  weight.  "When  in  motion, 
it  is  strong  enough  to  uproot  the  loftiest  trees, 
and  overturn  the  most  substantial  monuments,  to 
toss  the  ocean  in  furious  billows,  and  shatter  the 
proudest  vessels  as  though  they  were  but  toys. 

"  The  atmosphere  heats  and  cools,  by  turns, 
the  earth  and  all  the  creatures  that  inhabit  it. 

"  It  drinks  up  the  mists  which  it  holds  aloft 
in  overarching  clouds,  and  then  showers  them 
down  in  rain  or  dew  upon  the  thirsty  ground. 

"  It  refracts  and  reflects  the  rays  of  the  sun, 
in  order  that  it  may  give  us  dawn  and  twilight, 
and  make  the  heavens  glow  with  dazzling  colors 
when  the  great  luminary  rises  and  sets. 

"  Were  it  not  for  the  atmosphere,  the  sun 
would  come  to  us  and  leave  us  abruptly,  and  we 
should  pass  without  transition  from  the  gloom  of 
midnight  to  the  blaze  of  noon.  We  should  no 


THE   ATMOSPHEEE.  15 

longer  enjoy  the  soft  radiance  of  twilight,  nor 
would  the  clouds  any  longer  shade  the  earth  to 
protect  it  from  the  burning  heat  of  the  day. 

"  The  atmosphere  brings  us  the  elements  that 
sustain  the  flame  of  life,  as  they  do  the  fire  on 
the  hearth  ;  and  it  receives  and  transmutes  in  its 
breast  all  the  deleterious  substances  thrown  off  by 
decomposition.  By  its  circulation  it  brings  us  all 
together  in  a  common  life  of  interchange  and 
mutual  dependence.  A  gaseous  substance  which 
would  be  fatal  to  us,  to  wit,  the  carbonic  acid 
which  we  constantly  inhale  and  throw  off,  it  dis- 
perses over  every  part  of  the  globe. 

"  The  date-palms  of  the  Nile,  the  cedars  of 
Lebanon,  the  cocoa-nut-trees  of  Tahiti,  imbibe  it  to 
improve  their  growth,  and  the  palms  and  banana- 
trees  of  Japan  transform  its  poisonous  breath 
to  flowers.  That  healthful  substance,  the  oxygen 
which  we  breathe,  comes  from  the  magnolias  of 
the  Susquehanna ;  the  splendid  trees  that  fringe 
the  Amazon  and  Orinoco;  the  giant  rhododen- 
drons of  the  Himalayas ;  the  roses  and  the  myr- 
tles of  Cashmere ;  the  cinnamon-trees  of  Ceylon, 
and  the  ancient  forests  that  stud  the  interior  of  Af- 
rica. All  contribute  to  supply  the  agent  of  life."  * 

1  See  Dr.  Buist,  in  the  Transactions  of  the  Bombay  Geographical 
Society,  vol.  ix.,  1850. 


16     METEOKS  AND  METEORIC  PHENOMENA. 

THE  AZURE  VAULT  OF  THE  SKY. THE  PROLONGATION 

OF  DAYLIGHT. 

The  uppermost  regions  of  the  atmosphere  are 
not  illuminated  by  daylight.  They  are  given  over 
to  eternal  night.  At  a  certain  height,  we  begin 
to  see  the  diffused  radiance  produced  by  the  parti- 
cles of  the  air  acting  on  the  rays  of  the  sun,  like 
the  thousand  facets  of  a  crystal,  gradually  die 
out.  To  the  eyes  of  aeronauts  at  the  height  of 
eight  or  ten  thousand  feet  above  the  earth's  surface, 
the  stars  seem  to  be  shining  through  the  deepest 
night,  while  beneath  them  the  earth  is  glowing 
with  the  sun.  The  beautiful  blue  tint  that  appears 
to  us  to  belong  to  the  sky  itself  is  really  only  that 
of  the  air  beheld  in  masses.  It  grows  darker 
above  the  luminous  region  that  immediately  sur- 
rounds us. 

The  vault  that  we  seem  to  gaze  upon  does  not 
exist.  The  atmospheric  layers,  augmenting  in 
density  as  they  approach  the  terrestrial  surface, 
lend  this  deceptive  appearance  to  the  sky.  It 
took  a  long  time  to  overcome  this  illusion,  and  to 
establish  the  fact  that  the  form  and  the  dimen- 
sions of  the  celestial  vault  change  with  the  condi- 
tion of  the  atmosphere,  its  opaqueness  or  trans- 
parency, and  its  greater  or  less  degree  of  illumina- 
tion. 


THE  AZURE  VAULT  OF  THE  SKY.        17 

The  rays  of  the  sun  are  partly  extinguished 
in  the  air  through  which  they  pass.  Their  dim- 
inution is  much  less  at  the  zenith  than  at  the 
horizon,  where  they  have  to  traverse  a  layer  of  the 
atmosphere  fifteen  times  as  thick.  Thus  we  can 
fix  our  gaze  upon  the  great  luminary  without  be- 
ing dazzled  when  it  has  just  risen.  A  modifica- 
tion of  the  same  nature  takes  place  in  terrestrial 
objects  which  are  less  and  less  easily  seen  as  their 
distance  augments — "  '  tis  distance  "  "  robes  the 
mountain  in  its  azure  hue." 

This  tint  so  peculiar  to  the  atmosphere  is  fre- 
quently altered  by  the  watery  particles  which  it 
contains,  and  which  generally  throw  off  white 
light ;  this  serves  to  explain  the  variations  observ- 
able in  the  sky  where  the  blue  is  more  decided  at 
the  zenith  than  at  the  horizon.  The  color  of  the 
same  part  of  the  sky  often  changes  in  the  course 
of  the  day.  It  grows  deeper  and  deeper  as  we 
advance  from  morning  until  noon,  and  then  insen- 
sibly fades  until  evening. 

A  very  simple  experiment  will  assist  us  in 
comprehending  that  property  of  light  which  is 
called  refraction.  Put  a  penny  on  the  bottom  of 
a  wide  empty  vase,  or  basin,  and  step  back  until 
the  coin  is  hidden  from  your  view ;  then,  with- 
out changing  your  position  again,  you  will  see  the 


18  METEORS    AMD   METEORIC   PHENOMENA. 

penny  come  into  view  whenever  some  water  is 
poured  into  the  basin.  This  is  because  the  light 
follows  a  broken  line,  and  the  same  thing  happens 
whenever  it  has  to  pass  from  a  volume  of  air  of 
greater  to  one  of  less  density.  In  like  manner 
may  we  explain  that  other  phenomenon  of  the  at- 
mosphere which,  by  refracting  the  rays  of  the  sun, 
causes  us  to  see  it  at  a  greater  elevation  than  the 
real  one,  and  thus  perceptibly  increases  the  length 
of  the  day. 

Before  rising,  the  sun  illuminates  the  higher 
ranges  of  cloud,  and  they  reflect  his  light  to  us. 
This  light  gradually  increases  until  his  disk  ap- 
pears. The  directly  opposite  effect  takes  place  in 
the  evening,  when  the  sun  is  setting.  Who  has 
not  often  admired  those  successive  transitions, 
those  struggles  between  day  and  night,  that  offer 
so  sublime  a  spectacle,  endlessly  varied  by  the  thou- 
sand colors  of  the  vapors  spread  along  the  horizon, 
and  the  clouds  that  float  in  the  sky  ? 

THE   COLORS    OF   THE    SOLAR    SPECTRUM. 

If  we  cause  the  solar  light  to  pass  through  a 
prism  of  crystal,  it  produces  a  colored  spectrum. 
This  spreading  forth  of  different  hues,  which  has 
an  almost  magical  effect,  is  produced  by  the  de- 
composition of  a  white  ray  into  several  kinds  of 


THE   COLORS    OF   THE    SOLAR   SPECTRUM.  19 

light,  of  which  the  seven  principal  hues  follow  each 
other  in  the  subjoined  order  : 

Violet,  indigo,  Hue,  green,  yellow,  orange, 
red. 

That  property  of  the  atmosphere  which  pro- 
duces this  phenomenon  is  designated  in  science  by 
the  name  of  dispersion. 

Mr.  Forbes,  an  English  physiologist,  has  made 
and  described  a  very  curious  observation  of  the 
play  of  light  in  vapors  suspended  in  the  air. 
This  observation  assists  us  in  comprehending  the 
phenomena  visible  during  the  morning  and  even- 
ing twilight. 

Mr.  Forbes  was  standing  near  a  locomotive  that 
was  about  to  start,  and  was  looking  at  the  image 
of  the  sun  reflected  in  the  column  of  steam  that 
issued  from  the  'scape-pipe. 

Immediately  over  the  orifice,  the  vapor  was 
clear  and  transparent  like  the  air.  The  sun's  rays 
passed  it  without  diminution  of  strength,  and  fell 
upon  a  white  wall  opposite.  A  little  higher  up, 
the  light  appeared  less  vivid,  but  the  color  was 
orange,  and  the  half  shade  thrown  upon  the  wall 
reminded  the  observer  of  the  first  tints  of  evening. 
The  disk  of  the  sun  just  above  it  was  of  a  deep- 
red  color.  Beyond  that  the  steam,  before  resolv- 
ing itself  into  drops  of  water,  would  not  allow 


20  METEORS    AND   METEORIC   PHENOMENA. 

the  rays  to  pass,  and  its  shadow  was  completely 
dark. 

SUNSET. 

On  the  Atlantic  Ocean,  near  the  coast  of 
Portugal,  we  have  noticed  twilight  in  which  the 
colors  of  the  spectrum  succeeded  each  other  with 
great  regularity,  from  bluish  green  to  vivid  red. 
These  modifications  are  slow  in  our  climate  ;  they 
permit  us  to  enjoy  fully  the  magic  spectacle  of 
those  twilight  scenes  in  which  the  sombre  blue  of 
the  sea  heightens  the  delicate  hues  of  the  sky. 
Near  the  equator,  the  duration  of  the  phenomenon 
is  much  less,  but  it  is  generally  extremely  beauti- 
ful. M.  Liais,  a  French  astronomer  of  eminence, 
has  thus  described  it  in  the  narrative  of  his  voy- 
age to  Rio  Janeiro : 

"  Almost  immediately  after  the  setting  of  the 
sun,  a  rosy  tinge  is  seen  in  the  east.  Then  there 
soon  becomes  visible  above  it  a  dark  segment  of 
sky,  frequently  of  a  greenish  color.  The  rosy  hue 
extends  and  broadens  toward  north  and  south,  and, 
eleven  minutes  after  its  appearance  in  the  east, 
begins  to  be  seen  in  the  west,  the  zenith  remaining 
blue.  In  reality,  a  rosy  coloring  exists  all  aroTind 
the  zenith,  clear  to  the  horizon,  excepting  at  the 
east,  where  a  grayish  blue  or  greenish  gray  rests 
on  the  horizon,  and  at  the  west,  where  a  white 


SUNSET.  21 

segment  may  be  noticed.  Eight  minutes  after  its 
appearance  in  the  west,  the  rosy  coloring  which 
had  remained  all  the  time  at  the  west,  but  was 
gradually  growing  feebler,  disappears  altogether 
on  that  side.  At  the  west  can  be  distinguished  a 
white  segment,  bordered  with  an  arc  of  vivid  rose- 
color,  above  which  appears  the  deep  azure  with 
a  splendor  and  intensity  of  tint  impossible  to 
describe.  This  arc  descends,  gradually,  toward 
the  horizon.  It  then  becomes  greatly  flattened 
and  assumes  a  vivid  scarlet  or  orange  red.  It 
sets,  at  length,  when  the  sun  is  11°  below  the 
horizon. 

"  "When  the  red  arc  is  very  low,  and  on  the 
point  of  disappearing  at  the  west,  a  second  rosy 
coloring  appears  gradually  and  simultaneously  at 
the  west  and  the  east,  making  a  complete  circuit 
of  the  zenith,  which  remains  blue  all  the  time. 
At  the  west,  a  space  of  silvery  white  separates  the 
two  rose-colored  arcs.  By  degrees,  as  the  sun  de- 
scends, the  second  rosy  coloring  is  seen  to  disap- 
pear first  at  the  east,  withdrawing  toward  the 
north  and  south  without  passing  by  the  zenith. 
Then,  at  last,  the  first  rose-colored  arc  sets,  and 
there  remains  only  the  second  arc,  which  is  in 
the  west,  and  has  the  form  of  a  flattened  arch,  with 
a  white  segment  below  it.  Finally,  this  second 


22  METEOES   AND   METEORIC   PHENOMENA. 

rose-colored  arc,  which  assumes  a  still  redder  hue 
as  it  descends,  sets  when  the  sun  is  18°  below  the 
horizon." 

We  will  also  quote  the  description  of  a  sunset 
on  the  Desert  of  Sahara,  as  given  by  M.  Charles 
Martins  in  the  Revue  des  Deux  Mondes,  August 
15,  1864 : 

"  Each  sunset  was  a  veritable  feast  for  our  eyes, 
and  a  delight  as  well  as  a  source  of  astonishment 
for  the  mind,  especially  when  the  atmosphere  was 
not  completely  serene.  The  coloring  of  the  sky  is 
then  more  vivid  and  more  varied.  Gradually,  as 
the  sun  approaches  the  horizon,  the  gray  dishev- 
elled clouds  of  the  overarching  sky — those  latest 
emissaries  of  the  northern  mists  and  fogs — become 
fringed  with  purple  tints  that  grow  more  and  more 
intense,  while  the  rounded  contours  of  the  white 
clouds  reposing  on  the  distant  summits  take  on  a 
yellow  bordering,  and  seem  to  be  set  and  chased 
in  the  rich  gold  that  fills  the  western  heavens.  So 
soon  as  the  sun  has  descended  below  the  horizon, 
the  softest  ruddy  tint  spreads  over  the  whole 
western  sky.  An  emanation  of  the  departed  lu- 
minary, it  colors  all  the  mountains.  One  of  these, 
visible  from  Biskra,  is  called  Djebel-IIammar- 
I&eddou — the  mountain  with  the  rosy  cheek.  It 
deserves  this  name,  because,  long  after  the  setting 


SUNSET.  23 

of  the  sun,  it  retains  a  rosy  hue,  like  the  blush 
of  a  young  girl.  Through  the  effect  of  contrast 
with  the  red,  the  blue  of  the  sky  assumes  a  watery- 
green  tinge.  Little  by  little  the  rose-color  fades,  the 
illuminated  arc  contracts,  and  the  light  that  shines 
on  it  is  as  white  and  pure  as  that  which  should  glow 
in  the  realms  of  space  beyond  the  limits  of  our  at- 
mosphere. Thanks  to  the  transparency  of  the  at- 
mosphere, all  the  outlines  of  terrestrial  objects  are 
clearly  defined.  The  delicate  edges  of  the  leaves 
of  the  palm-tree  become  more  visible  than  in  the 
full  light  of  day,  and  when  the  whole  tree  stands 
out  against  these  backgrounds  of  alternate  yel- 
low, red,  and  white,  it  seems  as  though  the  poetic 
beauty  of  this  noble  plant  were  revealed,  for  the 
first  time,  to  the  gaze.  However,  night  comes  on. 
The  planets  and  then  the  grand  constellations 
first  appear ;  the  sky  becomes  peopled  with  myr- 
iads of  stars.  The  upper  vault  grows  brighter, 
and  the  milky  way,  which  is  but  a  dim,  whitish 
belt,  as  seen  in  the  higher  latitudes,  looks  like  a 
sparkling  scarf  of  diamonds  flung  athwart  the 
celestial  dome.  The  moon  is  no  longer  that  pal- 
lid star  whose  melancholy  glance  seems  to  sympa- 
thize with  the  dulness  of  our  foggy  regions  ;  it  is 
a  glowing  disk  of  the  purest  silver,  that  reflects 
without  weakening  the  rays  that  it  receives,  or  is 


'24  METEORS    AND   METEORIC   PHENOMENA. 

a  crescent  rounded  off  to  the  full  orb,  by  the  ashy 
radiance  which  distinctly  and  sharply  defines  the 
entire  outline.  Such  was  the  sunset  of  December 
13,  1863,  on  the  evening  before  our  departure  from 
Biskra  ;  it  affected  us  deeply,  for  it  was  our  adieu 
to  our  evenings  on  the  desert." 

THE   TWILIGHT   OF   THE   POLAR  REGIONS.  -  THE  ANTI- 
TWILIGHT. 

The  rule  generally  admitted  for  the  duration 
of  the  twilight  is  the  descent  of  the  sun  18°  below 
the  horizon.  In  many  places,  however,  it  lasts 
all  night,  at  certain  periods  of  the  year?  In  the 
Scandinavian  countries,  in  northern  Germany, 
and  even  as  low  down  as  the  latitude  of  Paris, 
this  is  the  case  about  the  period  of  the  summer 
solstice. 

When  the  upper  regions  of  the  atmosphere 
are  filled  with  fine  particles  of  ice,  the  darkness  is 
not  complete  even  when  the  sun  is  30°  below  the 
horizon,  as  the  long  twilights  of  the  polar  regions 
sufficiently  prove.  In  those  gloomy  countries  there 
reigns,  during  the  six  months'  night,  a  sort  of  half 
daylight,  which  is  sometimes  strong  enough  to 
read  by,  should  the  effulgence  of  the  moon  and 
the  radiance  of  the  aurora  ~borealis  aid  the  pale 
emanations  of  the  sun. 
9U^ie~~~  **•  *"?•• 

,< 


» 


iliWIJiifiiiii!1  II 


THE    MIRAGE.  25 

Very  frequently  one  may  notice,  after  the  set- 
ting of  the  sun,  when  one  is  standing  on  an  emi- 
nence, a  red  arch  defined  upon  the  eastern  sky 
around  a  darkish-blue  space.  Under  favorable 
circumstances,  the  line  of  separation  is  marked  by 
a  yellowish  edging.  This  is  the  phenomenon  that 
has  been  styled  the  anti-twilight.  The  apex,  or 
culminating  point  of  the  arch,  is  directly  opposite 
the  sun,  and  attentive  examination  shows  that  the 
segment  illuminated  only  by  the  scattered  rays 
corresponds  with  the  shadow  of  the  earth  pro- 
jected against  the  sky. 

THE   MIRAGE. 

If  in  summer  we  look  at  objects  visible  across 
a  field  heated  by  the  sun,  they  seem  to  waver  and 
their  shapes  continually  change.  This  effect  is 
accounted  for  by  the  crossing  and  recrossing  of 
thin  streams  of  cold  and  warm  air  rising  and  de- 
scending. The  luminous  rays  in  passing  through 
them  modify  their  movements  at  nearly  every  in- 
stant. 

The  phenomenon  known  as  the  mirage,  of 
which  the  most  remarkable  examples  are  met 
with  in  Egypt,  have  an  analogous  origin.  In  that 
country  the  atmosphere  is  usually  calm  and  ex- 
tremely pure.  At  sunrise  remote  objects  can  be 


26  METEOKS    AND    METEORIC   PHENOMENA. 

seen  with  the  most  perfect  distinctness.  From 
the  borders  of  the  Nile  to  the  limits  of  the  Des- 
ert, arise,  from  point  to  point,  small  eminences 
crowned  with  villages  and  groves  of  palm-trees, 
which  look  down  upon  each  year's  inundation  of 
the  river.  Gradually,  as  the  sun  climbs  above  the 
horizon,  the  ground,  becoming  heated,  imparts 
its  superior  temperature  to  the  lower  strata  of  the 
atmosphere.  At  such  times,  the  undulating, 
tremulous  motion  of  which  we  have  spoken  is  fre- 
quently noticed.  But  when  there  is  no  wind,  and 
the  dead  calm  of  the  atmosphere  allows  the  lower 
strata  to  expand  without  commingling  with  those 
that  are  resting  upon  them,  the  spectator  might 
fancy  that  he  had  before  him  a  huge  lake,  in 
the  midst  of  which  are  seen  the  reversed  images 
of  the  surrounding  eminences  and  the  villages 
that  are  built  upon  them.  The  magnificent  blue 
sky  seems  to  be  reflected  in  it  too;  but,  as  one 
approaches,  the  imaginary  sheet  of  water  fades 
away,  leaving  only  the  burning  sands  in  its  place, 
while  farther  on  the  same  deceptive  picture  is 
reproduced  under  a  different  aspect. 

These  appearances  often  misled  the  French 
troops  in  Egypt.  Worn  out  with  forced  marches, 
dying  of  thirst  under  the  scorching  heat  of  an 
African  sun,  and  choked  by  the  clouds  of  sand  that 


THE    MIRAGE.  27 

filled  the  air,  they  would  rush  headlong  toward 
the  fancied  water  before  them,  but  the  delusive 
shore,  alas  !  always  fled  farther  and  farther  at  their 
approach. 

To  the  distinguished  savant  Monge,  who  ac- 
companied the  French  expedition  into  Egypt,  is 
due  the  elucidation  of  this  phenomenon.  He  has 
demonstrated  that  the  most  rarefied  strata  of  air, 
in  this  case,  being  the  lowermost,  a  luminous 
ray  darting  from  an  elevated  object  toward  the 
ground,  deflects  more  and  more  in  consequence  of 
refraction,  up  to  the  moment  when  it  is  reflected 
from  a  last  stratum,  as  it  would  be  from  a  mirror, 
and  then  rises  again,  subject  to  a  series  of  refrac- 
tions the  reverse  of  those  first  encountered.  It 
thus  at  last  strikes  the  eye  of  the  observer  in  the 
same  direction  as  though  it  came  from  a  point  sit- 
uated below  the  level  of  the  soil,  presenting  the 
reversed  images  as  they  would  appear  if  he  saw 
them  on  the  surface  of  a  placid  lake. 

Mariners  frequently  get  a  view  of  the  mirage 
under  circumstances  the  opposite  of  those  that  we 
have  just  set  forth.  The  temperature  of  the  sea, 
being  colder  than  that  of  the  superincumbent 
strata  of  air,  renders  them  less  dense  below  than 
above,  and  the  reversed  picture  of  distant  shores 
or  vessels  is  defined  on  the  atmosphere  itself. 


28  METEORS   AND    METEOEIO   PHENOMENA. 

Captain  Scoresby  made  many  such  observations 
in  the  waters  of  Greenland. 

"  On  the  19th  of  June,  1822,"  says  this  accom- 
plished navigator,  in  one  of  his  narratives,  "  the  sun 
was  very  warm,  and  the  coast  seemed  suddenly 
to  come  from  fifteen  to  twenty  miles  nearer.  The 
highlands  were  raised  so  much  to  the  view  that  we 
could  see  them  as  well  from  the  deck  of  the  ship 
as  we  could  previously  from  the  foretop.  The  ice 
on  the  horizon  assumed  the  most  singular  forms ; 
huge  blocks  looked  like  pillars  and  columns ;  the 
icebergs  and  field-ice  resembled  a  chain  of  pris- 
matic rocks,  and  at  many  points  the  ice  appeared 
to  be  in  the  air  at  a  considerable  height  above  the 
horizon.  The  ships  that  happened  to  be  near  us 
had  the  most  fantastic  aspect.  On  some  of  them 
the  mainsail  seemed  to  be  reduced  to  a  mere 
nothing,  while  the  foresail  looked  several  times  as 
large  as  it  really  is. 

"  Above  the  vessels  at  a  distance,  we  saw  an  ex- 
act picture  of  themselves,  but  reversed  and  mag- 
nified. In  some  cases  this  was  at  quite  an  eleva- 
tion above  the  ship,  but  then  it  was  always  smaller 
than  the  original.  For  some  minutes  we  saw  the 
image  of  a  vessel  that  was  really  below  the  horizon, 
and  one  ship  was  surmounted  by  a  picture  of  two 
like  it,  the  one  upright  and  the  other  reversed." 


THE   MIRAGE.  29 

Among  the  numerous  varieties  of  this  phe- 
nomenon of  the  mirage,  the  one  observed  by 
Messrs.  Soret  and  Jurine  on  the  Lake  of  Geneva, 
which  might  be  correctly  styled  the  lateral  or 
horizontal  mirage,  is  hot  the  least  curious.  These 
gentlemen  were  at  a  window  in  the  second  story  of 
a  house  close  to  the  shore,  and  were  looking  with 
a  spy-glass  at  a  number  of  sail-boats  passing  from 
right  to  left,  in  the  middle  of  the  lake,  while, 
nearer  to  the  shore,  the  same  fleet  of  boats  ap- 
peared to  be  sailing  in  exactly  the  opposite  direc- 
tion !  This  was  an  illusion  analogous  to  the 
Egyptian  mirage,  and  explicable  in  the  same  way. 
Close  to  the  shore  the  air  had  been  in  the  shade  a 
part  of  the  morning,  and  was  comparatively  cool- 
er, while  out  in  the  open  lake  it  had  been  heated 
by  the  blaze  of  the  sun.  Hence,  vertical  strata 
of  air  of  different  densities  had  remained  motion- 
less, or  nearly  so,  in  the  prevailing  calm,  and  re- 
fraction had  produced  its  magical  effects  from 
side  to  side,  instead  of  above  and  below,  as  in 
the  cases  previously  detailed. 

When,  instead  of  occurring  in  level  and  regu- 
lar strata,  these  effects  of  refraction  and  reflection 
take  place  in  curved  and  irregular  strata,  a  mi- 
rage is  produced  in  which  the  images  are  distorted 
in  every  respect,  broken  or  repeated  over  and  over 


30  METEORS   AND  METEORIC   PHENOMENA. 

again,  and  separated  for  considerable  distances 
from  each  other.  This  is  what  takes  place  in  the 
fantastic  aerial  vision  formerly  ascribed  to  the  fairy 
Fata  Morgana,  and  sometimes  attracts  multitudes 
to  the  sea-shore  at  Naples,  and  at  Reggio  on  the 
Sicilian  coast. 

"  For  an  extent  of  several  miles  along  the 
coast  of  Sicily,"  says  an  eye-witness  of  this  extraor- 
dinary spectacle,  "  I  saw  the  sea  assume  the  ap- 
pearance of  a  chain  of  gloomy  mountains,  while 
the  waters  in  the  direction  of  Calabria  remained 
perfectly  smooth.  Above  them  was  seen,  in 
chiaro-oscurOj  a  range  of  many  thousand  pillars, 
all  of  equal  height,  distance,  and  degrees  of  light 
and  shade.  In  the  twinkling  of  an  eye,  these 
pilasters  lost  half  their  height,  and  seemed  to 
bend  over  and  resolve  themselves  into  arches  and 
arcades  like  the  old  Roman  aqueducts.  Then  a 
cornice  formed  along  the  top,  and  an  endless  num- 
ber of  castles,  all  alike,  appeared.  These  pres- 
ently faded  away  into  towers  that  vanished  also, 
leaving  nothing  visible  but  a  long  colonnade,  suc- 
ceeded in  its  turn  by  windows,  and  then  by  pines 
and  cypresses  also  indefinitely  repeated." 

Sometimes  these  objects  are  depicted  in  the 
sky  at  a  great  height  above  the  ground.  On  such 
occasions  some  of  them  are  in  rapid  motion,  while 


THE   MIRAGE.  31 

others  are  at  rest.  Their  outlines  often  gleam 
with  rainbow  colors,  and,  as  the  light  augments, 
their  form  becomes  more  and  more  aerial,  until 
they  melt  away  and  disappear  when  the  sun  shines 
forth  in  all  his  splendor. 

Bernardin  de  Saint  Pierre  relates  the  follow- 
ing incidents :  "  A  very  singular  phenomenon 
was  once  described  to  me  by  our  celebrated  paint- 
er, Yernet,  who  was  my  friend.  During  his  youth, 
when  in  Italy,  he  devoted  himself  particularly  to 
the  study  of  the  sky,  a  more  interesting  branch 
of  his  art,  no  doubt,  than  the  study  of  the  antique, 
since  it  is  from  the  sources  of  light  that  the  colors 
and  aerial  perspectives  issue  that  form  the  charm 
of  pictures  as  well  as  of  Nature  itself.  Yernet,  in 
order  to  fix  their  variations,  had  conceived  the  idea 
of  painting  on  the  leaves  of  a  book  all  the  shad- 
ings  of  each  principal  color,  and  then  had  marked 
them  with  different  numbers.  When  he  was  de- 
signing a  sky,  after  having  sketched  out  his  rough 
draft  and  the  forms  of  the  clouds,  he  would  rapid- 
ly note  down  all  the  fugitive  tints  on  his  canvas 
with  figures  corresponding  to  those  in  his  book, 
and  then  color  them  at  his  leisure.  One  day  he 
was  greatly  astonished  to  see  in  the  sky  the  ap- 
pearance of  a  city  reversed.  He  could  perfectly 
distinguish  the  steeples,  the  towers,  and  the 


32  METEORS    AND   METEORIC   PHENOMENA. 

houses.  He  hurriedly  made  a  sketch  of  the  phe- 
nomenon, and  then,  determined  to  know  the  cause 
of  it,  he  set  out,  following  the  direction  of  the  wind, 
into  the  mountains.  But  what  was  his  surprise 
when,  some  twenty  miles  distant,  he  found  the 
very  city  the  spectre  of  which  he  had  beheld  in 
the  sky,  and  had  a  sketch  of  in  his  portfolio !  " 

It  is  perhaps  to  the  effects  of  mirage  that  we 
must  attribute  the  extraordinary  faculty  of  sight 
once  so  famous  on  the  lie  de  France.  Toward 
the  close  of  the  last  century,  a  colonist  named 
Bottineau  could  make  out  vessels  which  were  still 
a  considerable  distance  below  the  horizon.  The 
new  science  which  he  pretended  to  have  con- 
structed, by  combining  the  effects  produced  by  dis- 
tant objects  upon  the  water  and  upon  the  atmos- 
phere, he  called  Namcopy.  He  went  to  Paris, 
provided  with  letters  from  the  intendant  and  the 
governor  of  the  island,  attesting  the  reality  of  hi» 
discovery ;  but  he  could  not  even  succeed  in  ob- 
taining an  audience  with  M.  de  Castries,  who  was 
then  Minister  of  Marine.  No  one  took  the  pains 
to  investigate  the  means  by  which  he  mastered 
such  surprising  results.  In  the  latter,  Arago  was 
not  altogether  an  unbeliever,  as  we  glean  from  his 
efforts  to  discover  whether  certain  phenomena  of 
the  twilight,  in  which  the  shadows  of  distant 


THE   MIRAGE.  33 

mountains  probably  play  a  part,would  not  help  to 
clear  up  this  important  secret.  The  poor  colonist 
returned  to  his  home  on  the  Isle  of  France,  where 
he  was  afterward  seen  passing  most  of  his  time, 
until  he  died,  on  the  sea-shore,  his  gaze  fixed  on 
the  horizon,  and  continuing  to  excite  the  amaze- 
ment of  all  by  the  accuracy  of  his  predictions. 


CHAPTEE  II. 

CLOUDS    AND    FOGS. 


The  Clouds.— Formation  of  the  Clouds  and  Mists.— Influence  of  the  Ma- 
rine Currents.— Extraordinary  Fogs.— Appearance  and  Motion  of  the 
Clouds.— Hail-Clouds.— Forms  of  the  Clouds.— Cloud-Rings.— Influ- 
ence of  the  Mountains. — Distribution  of  the  Clouds. — The  Spectre  of 
the  Brocken.— The  Shadow  of  Mont  Blanc. 


THE  CLOUDS. 

ARISTOPHANES,  in  his  play  of  The  Clouds,  puts 
the  following  invocation  into  the  month  of  Soc- 
rates : 

"  '  O  sovereign  master  !  thou  vast  air  that  dost 
envelop  all  parts  of  the  earth  ! — luminous  ether ! 
and  ye,  O  venerable  goddesses,  the  clouds,  mothers 
of  the  thunder  and  the  lightning ! — arise,  O  sover- 
eign clouds  !  and  appear  on  the  empyrean  heights. 
Come,  O  august  clouds  !  whether  ye  rest  on  the 
sacred  summits  of  Olympus,  white  with  snow  ;  or, 
in  the  plains  of  the  Ocean,  your  father,  ye  form 
dances  in  honor  of  the  nymphs ;  whether  at  the 
mouths  of  the  l^ile  ye  dip  up  his  waters  in  golden 
urns,  or  whether  ye  dwell  on  the  Palus  Mseotis, 


FORMATION   OF   THE   CLOUDS   AND   MISTS.          35 

or  upon  the  stormy  rock  of  Mimas,  hearken  to 
my  prayers,  and  receive  with  favor  the  sacrifice  I 
make.' 

"  Chorus  of  Clouds. — '  Eternal  clouds,  from  the 
resounding  bed  of  the  Ocean,  our  father,  let  us 
rise,  in  light,  transparent  mists,  to  the  woody 
summits  of  the  lofty  mountains,  that  we  may  look 
down  into  the  distance  upon  the  hilly  country ; 
the  sacred  earth,  prolific  of  fruits ;  the  courses  of 
the  rivers,  and  the  sea  whose  billows  dash  and 
break  roaring  against  the  crags !  For  the  eye 
of  the  heavens  blazes  eternally  with  dazzling  efful- 
gence. Let  us  scatter  and  dissolve  these  dull  mists 
that  enfold  us,  and  show  ourselves  to  the  earth 
in  our  immortal  beauty.' ': 

The  charm  of  this  poetry  lies  in  the  truth  as 
well  as  the  beauty  of  its  images ;  but  the  brief 
meteorological  sketch  which  Aristophanes  then 
gives,  according  to  the  theories  of  his  epoch,  is  an 
example  of  the  errors  that  must  follow  observation 
when  not  based,  as  it  is  to-day,  upon  knowledge 
of  the  physical  laws  the  influence  of  which  we 
are  about  to  describe. 

FORMATION   OF   THE   CLOUDS   AND   MISTS. 

The  formation  of  mists  and  clouds  is  due  to 
the  presence  of  watery  vapor  in  an  atmosphere 


36  METEORS    AND    METEORIC    PHENOMENA. 

colder  than  the  soil  in  which  this  vapor  becomes 
visible,  exactly  like  the  steam  that  rises  over  boil- 
ing water. 

The  minute  bodies  of  which  the  mist  is  com- 
posed are  hollow  globules,  resembling  soap-bub- 
bles, or  droplets  of  water,  the  diameter  of  which, 
measured  through  the  microscope,  is  smaller  in 
summer  than  in  winter.  This  diameter  increases 
also  when  rain  is  threatened. 

Fogs  being  generally  the  result  of  the  cooling 
of  the  atmosphere,  and  of  the  mingling  of  two 
currents  of  air  of  unequal  temperature  charged 
with  moisture,  they  are  seen  forming,  especially  at 
morning  and  evening,  and  chiefly  during  the  au- 
tumnal season,  over  rivers  and  lakes,  the  water  of 
which  is  then  much  warmer  than  the  atmosphere. 

The  formation  of  vapor  is  most  abundant 
when  the  air  is  the  dampest.  Kaemtz,  in  his 
"Course  of  Meteorology,"  cites  an  observation 
made  by  the  ancients  in  reference  to  the  volcano  of 
Stromboli :  "  When  this  volcano  is  covered  with  a 
cloud,  the  inhabitants  of  the  Lipari  Islands  know 
that  it  will  soon  rain :  but  this  does  not  happen, 
as  they  suppose,  because  the  volcano  is  more  ac- 
tive just  before  a  shower ;  it  is  because  the  air, 
laden  with  watery  vapor,  cannot  completely  dis- 
solve that  which  escapes  from  the  crater." 


INFLUENCE   OF   THE   MARINE    CURRENTS.          37 

Columns  of  mist  ascend  sometimes  at  certain 
points  where  the  nature  of  the  soil  and  vegetation 
give  rise  to  a  more  active  evaporation. 

After  heavy  rains,  and  when  the  sun  shines 
out  again,  these  mists  are  seen  appearing  on  the 
slopes  of  the  mountains,  where  the  ground  is 
nearly  always  either  arid  or  studded  with  woods, 
and  following  the  undulations  and  accidents  of 
the  surface. 

The  same  phenomenon  occurs  in  Switzerland 
above  lakes  the  temperature  of  which  is  more  or 
less  elevated,  according  to  whether  the  streams 
that  feed  them  do  or  do  not  issue  from  the  region 
of  eternal  snow. 

Mists  form  under  circumstances  also  that  are 
different  only  in  appearance  ;  for  instance,  when 
there  is  a  thaw,  and  the  air,  laden  with  humidity, 
mingles  with  the  colder  air  that  is  in  contact  with 
the  ice  that  still  covers  the  waters.  The  same 
cause  produces  the  summer  fogs  seen  along  rivers, 
especially  after  heavy  storms  of  rain. 

INFLUENCE   OF   THE   MARINE   CURRENTS. 

Marine  currents  of  elevated  temperature,  such 
as  the  Gulf  Stream,  occasion  frequent  fogs  on  the 
colder  coasts  against  which  they  beat.  The  dense 
fogs  of  Newfoundland  and  of  the  British  Islands 


38  METEORS   AND   METEORIC    PHENOMENA. 

are  ascribable  to  this  influence,  which  has  been 
noted  in  other  regions — the  Aleutian  Isles,  for 
instance,  lying  in  the  track  of  the  great  tepid 
current,  analogous  to  the  Gulf  Stream,  that  crosses 
the  North  Pacific. 

Lieutenant  De  Haven,  of  the  United  States 
Navy,  during  his  expedition  in  search  of  Sir 
John  Franklin,  saw,  at  the  northern  extremity  of 
Wellington  Channel,  a  dense  fog-bank  motionless 
and  suspended  in  the  air — a  water-sky,  rising,  to 
all  appearance,  above  the  Polar  Sea,  discovered  in 
1854  by  Dr.  Kane,  the  open  waters  of  which  are 
tempered  by  the  submarine  current  found  to  ex- 
ist in  Davis's  Strait. 

EXTRAORDINARY   MISTS. 

Mists  are  sometimes  of  remarkable  extent  and 
duration.  In  1821  and  1822  mists  of  this  kind 
occurred  in  England  and  France,  so  dense  that 
people  could  gaze  upon  the  sun  at  noonday  with 
the  naked  eye.  In  1783  a  similar  fog  covered 
nearly  all  Europe  for  the  lapse  of  a  month. 

We  read  in  a  "  Journal  of  the  Reign  of  Henry 
III.,"  published  in  the  French  language  : 

"  On  Sunday,  the  24th  of  January,  1588,  there 
rose  over  the  city  of  Paris  and  its  environs  so  dense 
a  fog,  lasting  from  noon  until  the  next  day,  as 


EXTRAORDINARY   MISTS.  39 

never  was  seen  before  within  the  memory  of  man. 
It  was  so  black  and  thick  that  two  persons  walk- 
ing together  in  the  streets  could  not  see  each  other, 
and  were  compelled  to  provide  themselves  with 
torches,  in  order  to  recognize  one  another,  when  it 
was  not  yet  three  o'clock.  Yery  many  wild  geese, 
and  other  flying  creatures  of  the  air,  were  found 
where  they  had  fallen  bewildered  in  the  court- 
yards of  the  houses,  having  dashed  themselves 
against  the  buildings  and  the  chimneys." 

Captain  Berg,  a  Russian  officer,  mentions  a 
sort  of  mist  that  appears  to  rise  from  the  sea  in 
stormy  weather,  and  is  called  smoke.  We  have 
repeatedly  witnessed  this  phenomenon,  which  is 
ascribable  partly  to  electricity.  M.  Peltier,  the 
French  savant,  in  one  of  his  learned  treatises, 
divides  mists  into  two  classes,  viz.,  the  electric  and 
the  non-electric.  He  explains  the  condition  of  the 
former  by  the  combined  influences  of  the  earth 
and  the  higher  regions  of  the  atmosphere.  More- 
over, it  has  been  ascertained  that  the  electric  fluid 
is  constantly  developed  in  the  atmosphere  sur- 
rounding cascades,  where  the  water  is  incessantly 
reduced  to  fine  spray,  and  this  remarkable  phe- 
nomenon might  lead  to  a  better  determination  of 
the  influence,  no  longer  to  be  denied,  of  atmospheric 
electricity  on  the  formation  of  aqueous  meteors. 


40  METEORS    AND   METEORIC   PHENOMENA. 

Luminous  mists  are  not  uncommon.  Mr. 
Wartmann,  of  Geneva,  in  a  letter  to  M.  Elie  de 
Beaumont,  given  in  the  Comptes  Rendus  of  the 
Academy  of  Sciences  of  Paris,  for  December  25, 
1859,  has  described  one  of  these  strange  meteors, 
which  continued  to  appear  for  nine  successive 
nights,  viz.,  from  the  18th  to  the  26th  of  Novem- 
ber, 1859.  The  new  moon,  which  was  below  the 
horizon,  could  not  contribute  to  this  phenomenon. 
The  mist,  which  was  very  opaque,  was  still  not 
moist  enough  to  dampen  the  ground.  It  threw 
oif  light  enough  to  enable  one  to  distinguish  the 
smaller  articles  in  a  room  where  the  observer 
stood.  A  person  who  was  proceeding  on  foot 
from  Geneva  to  Annemasse,  in  Savoy,  on  the  22d 
of  November,  stated  that  he  could  see  the  road 
during  the  night  as  well  as  he  could  have  done  by 
the  light  of  the  moon. 

Phosphorescent  mists  of  the  luminous  order  are 
usually  dry  mists,  like  those  of  1T83  and  1831,  to 
which  we  shall  refer  again  when  we  come  to 
igneous  meteors. 

Certain  mists  that  form  over  marshy  plains 
have  a  peculiar  odor,  occasioned  probably  by  the 
miasma  which  they  contain  and  bear  along  with 
them. 

In  regions  where  it  seldom  rains,  as  for  instance 


APPEARANCE   AND  MOTION   OF  THE  CLOUDS.      41 

at  Lima  and  around  it,  the  mists  caused  by  local 
circumstances  last  sometimes  for  a  part  of  the  year, 
serving  to  moisten  the  soil  and  maintain  the  fresh- 
ness of  the  vegetation. 

Mists  are  often  seen  forming  over  hollows 
where  the  water  is  nearly  always  colder  than  the 
air,  and  determines  the  collection  of  vapor  above 
it.  Humboldt  states  that  in  the  South  Sea  Islands 
the  shape  of  these  mists  frequently  reproduces  that 
of  the  hollows  exactly. 

APPEARANCE   AND   MOTION   OF   THE    CLOUDS. 

The  appearance  and  movements  of  the  clouds, 
the  formation  of  which  is  due  to  the  same  causes 
that  produce  the  mists,  are  to  be  numbered  among 
the  chief  indications  that  announce  to  us  the 
changes  brought  about  in  the  aerial  ocean  by  the 
variations  of  electric  tension,  temperature,  and 
humidity. 

Mountain-summits  are  often  enveloped  in 
clouds  produced  by  the  damp  air,  and  by  the 
watery  vapor  that  condenses  by  degrees  as  it  rises 
toward  those  colder  regions.  These  clouds  are 
very  frequently  observed  to  disperse,  as  they  get 
farther  away  from  the  mountain-tops  and  encoun- 
ter air-currents  of  a  more  elevated  temperature. 

"  Often,"  says  Kaemtz, "  dark  clouds  pass  rap- 


42  METEOES    AND   METEOEIC    PHENOMENA. 

idly  over  the  Hospice  of  Saint  Gothard  and  pre- 
cipitate themselves  in  heavy  masses  into  the  Yal 
Tremola.  One  would  think,  to  look  at  them,  that 
all  Lombardy  was  about  to  be  buried  under  a 
dense  fog  ;  but,  at  the  outlet  of  the  Yal  Tremola, 
it  is  already  dispersed  by  the  warm  currents  of  air 
ascending." 

During  very  violent  winds,  clouds  are  seen,  in 
consequence  of  like  circumstances,  clinging  to  the 
peaks  of  mountain-ridges,  and  apparently  motion- 
less, while  around  those  peaks  the  intervals  re- 
main perfectly  clear. 

The  appearance  of  remarkable  clouds  suspend- 
ed on  the  summits  of  lofty  mountains  sometimes 
announces  tempests,  always  preceded  by  atmos- 
pheric variations,  which  practice  in  observing 
natural  signs  teaches  us  to  recognize.  Thus, 
the  people  of  the  Cape  of  Good  Hope  prognosti- 
cate tempests  from  the  southwest  (so  formidable 
in  their  latitudes)  whenever  they  see  a  compact, 
lead-colored  cloud  gathering  around  the  summits 
of  their  highlands,  and  particularly  on  Table 
Mountain. 

ICE-CLOUDS. 

The  mists  that  form  on  the  surface  of  the 
ground,  either  in  the  depths  of  valleys  or  on  the 


ICE-CLOUDS.  43 

heights,  become  clouds  whenever,  carried  upward 
by  ascending  currents,  they  remain  suspended  in 
the  atmosphere  above  us.  Clouds  are  also  formed 
directly  in  the  air  by  the  meeting  of  two  winds 
laden  with  moisture  and  of  unequal  temperature, 
or  by  the  condensation  of  copious  vapors  which 
rise  toward  the  colder  regions  of  the  atmosphere. 

Sometimes  there  are  several  beds  of  cloud 
resting  one  above  the  other,  and,  generally,  the 
whiter  they  look,  the  higher  they  are. 

The  temperature  of  the  regions  that  the  clouds 
ascend  to  is  often  several  degrees  below  zero,  and, 
as  may  readily  be  understood,  they  are  then  com- 
posed of  icy  particles,  like  the  fine  needles  of  the 
mists  that  ascend  in  fleecy  masses  during  severe 
cold  weather,  and  are  often  seen  glistening  in  the 
sunlight. 

In  reference  to  this  subject  we  shall  cite  an 
important  observation  that  concerns  meteorology 
in  the  highest  degree.  It  was  enunciated  in  a  re- 
markable lecture  on  "  the  influence  exerted  upon 
vegetation  by  the  atmosphere." 

The  lecture  in  question  was  delivered  by  one 
of  the  most  learned  and  courageous  scientific  ex- 
perimentalists of  France,  Professor  J.  A.  Barral, 
before  the  Chemical  Society  of  Paris. 

"  On  July  25,  1850,  my  friend  M.  Bixio  and 


44  METEORS    AND   METEORIC   PHENOMENA. 

I  were  fortunate  enough  to  ascend  in  a  balloon 
beyond  the  stratum  attained  by  Gray-Lussac  in 
1804,  and  some  surprise  was  manifested  that  we, 
in  the  midst  of  a  violently-agitated  atmosphere5 
and  in  the  bosom  of  a  vast  ice-cloud,  should  have 
found  39°.7  (by  the  aid  of  numerous  and  delicate 
instruments  graduated  by  M.  Regnault),  or,  in 
other  words,  the  temperature  at  which  mercury 
solidifies,  in  the  same  region  where  Gay-Lussac 
had  noted  only  9°. 5,  when  the  air  was  calm  and 
the  sky  clear.  This  surprise  had  no  other  basis 
than  a  defective  interpretation  of  the  facts  already 
established.  At  the  present  day  we  have  to  ad- 
mit that,  even  in  the  very  highest  regions  of  the 
atmosphere  that  men  have  reached,  there  are  con- 
siderable variations  in  the  temperature  of  the  air 
as  well  as  upon  the  surface  of  the  earth.  A  cir- 
cumstance no  less  remarkable  is,  that,  in  mid- 
summer, clouds  of  more  than  four  thousand  yards 
in  thickness,  composed  of  numberless  little  needles 
of  ice,  may  be  seen  gliding  above  our  heads  at  a 
velocity  of  at  least  thirty  miles  an  hour.  In 
those  regions  where  eternal  silence  reigns,  and 
where  all  life  has  ceased,  are  condensed,  along 
with  the  last  watery  molecules  that  have  mounted 
from  the  bosom  of  the  earth  and  the  clouds,  those 
innumerable  exhalations  which  we  are  wont  to 


ICE-CLOUDS.  45 

term  the  impurities  of  the  atmosphere.  The  mat- 
ter contained  in  them  descends  again  with  the 
rain,  the  hail,  and  the  snow,  to  the  surface  of 
our  planet,  where  it  is  disseminated,  and  conveys 
to  the  barrenest  rock  the  elements  necessary  to 
support  vegetation,  which  may  thus  develop  and 
distribute  themselves  in  nearly  every  latitude, 
whatever  may  be  the  character  of  the  soil  that 
receives  the  fertilizing  shower.  The  lower  aerial 
strata  that  touch  the  surface  of  the  solid  crust  of 
our  globe,  and  the  doubly  extensive  surface  of  its 
seas  and  oceans,  after  having  become  laden  with 
various  materials,  dilate  by  the  effect  of  heat,  and 
then  ascend  until  they  meet  the  chill  that  con- 
denses them  in  the  higher  regions,  and  causes 
them  to  fall  again  to  the  surface.  Thus  a  contin- 
ual rising  and  falling  motion  is  produced  in  that 
atmospheric  belt,  between  four  and  five  miles  in 
thickness,  which  we  have  been  able  to  sound.  The 
rain  and  the  snow  are  formed,  and,  borne  far 
away  from  the  spot  which  saw  the  birth  of  the 
embryo  cloud,  they  go  forth  to  fertilize  distant 
plains  by  besprinkling  them  with  water  that  is 
saturated  with  a  new  air." 

In  England  the  latest  winter  ascensions  of  a 
learned  aeronaut,  Mr.  Glaisher,  enabled  him  to 
detect,  at  an  elevation  where  the  temperature  was 


4:6  METEORS    AND   METEORIC    PHENOMENA. 

very  low  during  the  summer  ascensions,  a  current 
of  warm  air,  seven  hundred  yards  in  thickness, 
charged  with  vapor.  The  latter  soon  afterward 
descended  upon  the  city  of  London  and  enveloped 
it  in  a  dense  fog. 

These  interesting  observations  go  to  prove  that 
the  loftier  regions  of  the  atmosphere  are  traversed, 
like  the  depths  of  the  ocean,  by  great  currents  of 
unequal  temperature,  which,  no  doubt,  contribute 
to  the  maintenance  of  a  general  system  of  aerial 
circulation,  and  which,  sometimes  descending  to 
the  surface  of  the  earth,  there  produce  those  great 
changes  of  temperature  that  meteorological  obser- 
vation will  one  day,  perhaps,  enable  us  to  foresee 
with  sufficient  accuracy. 

THE   FORMS   OF   THE   CLOTJDS. 

The  causes  which  determine  the  forms,  the 
color,  and  the  elevation  of  the  clouds,  are  not  yet 
known.  The  double  action  of  the  currents  of 
warm  air  which  ascend  from  the  earth  in  the  day- 
time and  the  horizontal  currents,  suffices  to  ex- 
plain the  suspension  in  the  atmosphere  of  the  vis- 
ible vapors,  heavier  as  the  latter  are  than  the 
medium  in  which  they  float.  According  to 
Presnel,  the  solar  heat  absorbed  by  the  clouds 
makes  a  sort  of  balloon  of  them,  which  rises  the 


THE  FOEMS  OF  THE  CLOUDS.          47 

higher  according  to  the  greater  elevation  of  the 
temperature.  It  is  owing  to  these  influences  that 
clouds  are  generally  higher  at  noon  than  toward 
evening. 

M.  Jamin,  in  his  course  of  lectures  at  the 
Sorbonne,  has  demonstrated  that  the  aqueous 
particles  whose  aggregation  makes  a  cloud,  are  in 
the  condition  of  full  droplets,  and  that,  when  the 
radius  of  these  droplets  is  sufficiently  small,  but 
little  effort  is  required  to  sustain  them  at  certain 
heights.  This  effort  is  always  supplied  by  the 
continual  displacements  going  on  in  the  atmos- 
phere. 

Dr.  Howard,  a  learned  English  writer  on  phys- 
ical and  meteorological  science,  was  the  first  who 
distinguished  in  the  clouds  the  four  leading  forms 
of  Cirrus,  Stratus,  Nimbus,  and  Cumulus.  He 
classifies  them  in  his  "  Essay  on  the  Modifications 
of  Clouds,  and  on  the  Principles  of  their  Produc- 
tion, Suspension,  and  Destruction,"  published  at 
London  in  1802. 

The  cirrus  consists  of  thin,  transparent  clouds, 
which  look  like  delicate  plumes,  and  are  always 
seen  at  a  great  height.  They  are  sometimes  ob- 
served in  parallel  bands,  or  in  filaments,  stretching 
north  and  south,  appearing  to  diverge  from  one 
point  on  the  horizon  and  to  converge  toward  an- 


48  METEORS    AND    METEORIC    PHENOMENA. 

other  diametrically  opposite.     "  Many  meteorolo- 
gists," says  M.  Charles  Martins,  "for  instance, 


FORMS   OF  THE   CLOUDS — THE   CIRRUS,   OR  CAT-TAILS. 

Howard,  Forster,  Peltier,  and  others,  think  that 
the  cirri  serve  as  conductors  between  two  distant 


centres  of  electricity  of  different  poles,  in  which 
the  fluid  is  seeking  an  equilibrium,  and  that  the 


THE  FOKMS  OF  THE  CLOUDS.          49 

flexibility  of  the  clouds  at  length  gives  them  the 
rectilinear  form  required  by  the  necessity  for  the 
shortest  possible  transit  from  one  focus  to  the 
other.  The  whiteness  of  the  cirri  arises  from 
the  icy  particles  and  snow-flakes  of  which  they 
are  composed.  Their  peculiar  appearance  has 
earned  for  them  the  various  titles  of  "  cat-tails" 


50  METEORS    AND   METEOEIC   PHENOMENA. 

" horse-tails"  " mackerel-sky"  etc.  They  nearly 
always  portend  a  change  of  weather. 

The  stratus  is  the  long  horizontal  belt  of 
smoke-colored  clouds  that  often  extends  across  the 
horizon  at  sunset,  and  that  may  be  seen  forming, 
on  fine  summer  evenings,  above  expanses  of 
water  and  damp  meadows.  These  cloudy  bands 
may  be  thick  and  extensive  enough  to  cover  the 
sky,  but  they  never  yield  rain. 

The  nimbus  is  a  mass  of  dense,  black  clouds, 
with  jagged  borders,  which  announce  rain  o'r 
storm.  Hence  a  cloud  of  any  kind  resolving  it- 
self into  rain  always  takes  the  form  of  the  nim- 
bus. 

The  cumulus  consists  of  what  we  may  term 
"the  fine -weather  clouds."  Their  whiteness, 
which  contrasts  with  the  blue  of  the  sky ;  their 
rounded,  half-spherical  forms ;  their  well-defined 
outlines,  make  it  easy  to  distinguish  them.  Piled 
up  on  the  horizon,  they  frequently  assume  the 
shape  of  lofty  snow-clad  mountains,  and  when  they 
are  seen  to  darken  at  the  same  time  that  the  lower 
bed  of  the  cloud  spreads  out  into  a  stratus,  rain 
may  be  expected. 

The  great  poet  Goethe,  who  was  also  a  distin- 
guished naturalist,  has  left  us  some  remarkable 
points  relating  to  meteorology.  We  will  quote  a 


THE  FORMS  OF  THE  CLOUDS.         51 

passage  from  one  of  his  learned  essays  on  the  sub- 
ject, as  epitomized  by  the  French  savant  Mar- 
tins, who  has  edited  the  great  German's  scientific 
lucubrations  on  natural  history : 

"When  Goethe  was  made  acquainted  with 
Howard's  theory,  he  hastened  to  verify  its  princi- 
ples, and  to  that  end  undertook  a  series  of  experi- 
ments and  observations.  These  observations  were 
chiefly  made  during  the  course  of  a  journey  in 
Bohemia,  between  the  23d  of  April,  1820,  and  the 
28th  of  May  in  the  same  year.  They  were  ac- 
companied by  considerations  of  a  general  charac- 
ter, to  which  we  would,  for  a  moment,  call  atten- 
tion. 

"  Goethe,  in  common  with  many  other  mete- 
orologists, distinguishes  three  regions  in  the  atmos- 
phere :  the  most  elevated  is  characterized  by  its 
dryness;  it  therefore  tends  to  absorb  the  moist- 
ure of  the  lower  strata ;  and  in  this  region  the 
sky  is  clear,  or  covered  with  a  few  clouds  disposed 
in  the  cirrus  form.  Goethe  did  not  remark  that, 
in  the  icy  heights  of  the  atmosphere,  the  vapors 
become  converted  into  snow,  and  that  the  cirrus 
is  made  up  of  masses  of  snow-flakes.  In  the  in- 
termediate regions  we  find  the  cumulus,  whose 
strange  and  ever-varying  forms  have  become  the 
object  of  many  superstitious  notions  among  the 


52  METEOES   AND   METEOEIO   PHENOMENA. 

dwellers  in  mountainous  districts.  Below  the 
cirrus  and  the  cumulus  extends  the  stratus,  which 
occupies  the  lowest  part  of  the  upper  atmosphere. 
"  The  higher  and  the  lower  regions  are  in  a 
state  of  perpetual  conflict.  Sometimes  the  upper 
regions  prevail,  and  the  cumuli,  being  rent  asunder, 
rise  and  are  scattered  abroad  in  the  form  of  fleecy 
particles.  Sometimes,  on  the  other  hand,  the 
lower  region  is  the  more  powerful ;  then,  the 
cumulus  is  lengthened  out  to  a  stratus,  and  the 
heaped-up  mass  of  clouds  becomes  a  nimbus  big 
with  rain.  The  formation  of  clouds  may  take  an 
opposite  course  :  dense  fogs  ascend  from  the  earth 
in  the  shape  of  elongated  strata,  and  group  them- 
selves into  thick  cumuli,  or  separate  and  form  the 
cirrus.  Goethe  holds  persistently  to  this  conflict 
between  the  higher  and  lower  regions  of  the  at- 
mosphere, and  claims  to  have  noticed  that  the 
east  and  north  winds  cooperate  with  the  action 
of  the  upper  regions,  and  those  of  the  west  and 
south  with  the  action  of  the  lower  layers." 

DISTRIBUTION   OP   THE    CLOUDS. THE   CLOUD-EING. 

The  distribution  of  the  clouds  in  different 
parts  of  the  globe  has  been  too  imperfectly  ob- 
served to  enable  us  to  deduce  any  general  laws 
therefrom.  Moreover,  this  distribution  is  evi- 


THE   CLOUD-KING.  53 

dently  in  direct  relation  to  the  quantity  of  rain 
that  falls  in  each  region,  and  we  shall  presently 
sum  up  the  data  thus  far  obtained  in  reference  to 
that  branch  of  meteorology  which  relates  directly 
to  cultivation  and  to  the  fertility  of  the  soil. 

This  fertility  is  not  due  merely  to  the  benefi- 
cent action  of  the  rain  that  waters  our  fields,  nor 
to  the  snow  that  protects  them  in  winter.  The 
clouds,  in  spreading  their  mantle  over  the  earth, 
keep  in  its  heat  or  prevent  excessive  drought, 
and,  as  Maury  has  well  said,  in  his  "Physical 
Geography  and  Meteorology  of  the  Sea,  "  "  when 
their  task  is  accomplished  at  one  point,  the  winds 
bear  them  away,  to  perform  the  same  regulating 
function  elsewhere." 

In  the  zone  of  the  equatorial  calms  one 
can  best  appreciate  this  influence  of  the  clouds 
upon  climate  and  vegetation.  While  in  the  re- 
gion of  the  trade-winds,  both  north  and  south 
of  the  equator,  the  sky  is  usually  clear  or  dotted 
with  light  clouds ;  we,  on  the  contrary,  when  ap- 
proaching the  zone  of  calms,  see  the  sky  become 
obscured  and  covered  with  dense  vapors,  arising 
from  the  masses  of  air  saturated  with  moisture 
which  the  trade- winds  continually  sweep  into  that 
zone.  The  dais  or  disk  of  clouds  thus  formed 
extends  around  the  globe  like  a  ring,  or  belt,  which 


54  METEORS   AND   METEOEIC   PHENOMENA. 

is  carried  from  the  north  to  the  south,  or  from  the 
south  to  the  north,  within  certain  limits,  accord- 
ing to  the  season,  alternately  protecting  the  dif- 
ferent parallels  that  it  covers  from  the  blaze  of 
the  sun,  and  bringing  them  rain  at  given  periods. 

INFLUENCE    OF    MOUNTAINS. THE    SPECTEE    OF    THE 

BBOCKEN. 

We  have  already  referred  to  the  influence  ex- 
erted by  mountains  on  the  condensation  of  vapors. 
M.  de  Gasparin,  in  his  "Rural  Meteorology," 
cites  quite  a  remarkable  observation  in  connection 
with  this  subject.  "  It  is  known,"  says  he,"  that 
the  narrow  passage  leading  into  the  harbor  of 
Plymouth  is  bounded  on  the  east  and  west  by 
two  promontories  covered  with  woods.  J.  Har- 
vey has  noticed  that  a  dense  and  quite  compact 
cloud,  coming  from  the  west,  disappeared  in  pass- 
ing over  the  strait  and  formed  again  upon  reach- 
ing the  opposite  point  of  land." 

The  abundance  of  clouds  in  mountainous 
countries,  their  capricious  forms,  and  frequently 
strange  distortions,  have  furnished  geniuses  and 
poets  with  beautiful  similes.  Popular  traditions 
show  us  that  these  natural  phenomena  have  long 
been  the  source  of  superstitions  that  have  not  yet 
entirely  died  out.  Thus,  in  certain  parts  of  the 


THE   SPECTRE   OF  THE  BROCKEN.  55 

V  osges  Mountains,  the  long,  black  trains  of  clouds 
that  unroll  and  wind  fiercely  down  through  the 
deep  gorges,  at  the  approach  of  storms,  still  in- 
spire terror,  as  a  token  of  the  presence  of  evil 
spirits  sweeping  by  with  the  tempest. 

A  wonderful  phenomenon,  the  Spectre  of  the 
Brocken,  was  long  explained  by  a  superstitious 
peasantry  as  the  work  of  direct  supernatural  in- 
tervention. One  of  the  best  descriptions  of  this 
phenomenon  was  given  by  Mr.  Hane,  who  wit- 
nessed it  on  May  25,  1797  :  "  After  having  scaled 
the  summit  of  the  mountain  more  than  thirty 
times,  in  vain,  at  last  he  had  the  good  fortune  to 
see  the  object  of  his  curiosity.  The  sun  rose  at 
about  four  o'clock  in  the  morning,  and  the  weather 
was  fine.  The  wind  was  driving  before  it  toward 
the  west  masses  of  transparent  vapor,  which  had 
not  yet  had  time  to  condense  into  clouds.  About 
a  quarter-past  four,  the  traveller  saw,  in  the  di- 
rection of  Achtermannshohe,  a  human  figure  of 
enormous  dimensions.  A  gust  of  wind  having 
nearly  blown  away  Mr.  Hane's  hat,  he  quickly 
put  up  his  hand  to  retain  it,  and  the  strange  fig- 
ure made  the  same  gesture.  Mr.  Hane  then  im- 
mediately made  another  motion,  stooping  down- 
ward, and  this  act  was  likewise  reproduced  by  the 
spectre.  Another  "person  joined  Mr.  Hane,  at 


56  METEORS   AND   METEORIC   PHENOMENA. 

this  moment,  and  the  two  gentlemen,  placing 
themself  together  on  the  very  spot  from  which 
the  apparition  had  been  noticed,  looked  toward 
Achtermannshohe,  but  saw  nothing.  However,  a 
little  while  afterward,  two  colossal  figures  ap- 
peared in  the  same  direction  imitating  the  motions 
and  gestures  of  the  two  observers,  and  then  dis- 
appeared. They  showed  themselves  again,  a  little 
later,  accompanied  by  a  third  figure.  Sometimes 
these  shapes  were  feeble  and  indistinct ;  at  others 
they  were  very  intensely  marked  and  their  out- 
lines sharply  defined.  The  reader  will  have 
guessed  that  the  phenomenon  was  produced  by 
the  shadow  of  the  spectators  projected  on  a  cloud. 
The  third  figure  was  undoubtedly  due  to  a  third 
person  half  hidden  behind  some  broken  mass  of 
rock." 

During  his  journey  with  La  Condamine 
among  the  Cordilleras,  Bouguer,  a  member  of  the 
French  Academy  of  Sciences,  sent  out  with  the 
former  to  South  America  to  measure  a  degree  of 
the  earth's  surface,  witnessed  a  phenomenon, 
similar  to  the  one  just  described,  from  the  sum- 
mit of  Pambamarca : 

"  What  astonished  us,"  says  he,  "  was  that  the 
head  of  the  shadow  was  adorned  with  a  halo 
formed  of  three  or  four  small  concentric  crowns 


THE  SPECTRE  OF  THE  BEOCKEN.        57 

of  very  vivid  color,  each  one  with  the  same  vari- 
ety as  the  first  rainbow,  the  red  on  the  outside. 
This  made  a  sort  of  apotheosis  for  each  spectator, 
and  I  must  not  forget  to  add  that  each  of  them 
tranquilly  enjoyed  the  pleasure  of  seeing  him- 
self decorated  with  all  these  crowns,  without  even 
catching  a  glimpse  of  those  of  his  neighbors." 

Kaemtz  has  verified  the  same  thing  on  the 
Alps.  So  soon  as  the  shadow  was  projected  on  a 
cloud,  the  head  was  seen  surrounded  by  a  lumi- 
nous halo.  Scoresby  in  the  polar  regions,  Ramond 
in  the  Pyrenees,  and  De  Saussure,  have  all  seen 
and  described  this  curious  phenomenon,  which  is 
known  under  the  name  of  Anthelia. 

Sometimes  it  is  observed  under  more  ordinary 
circumstances,  at  the  rising  and  the  setting  of  the 
sun,  when  fogs  are  resting  on  the  ground.  Fre- 
quently the  aerial  figure,  the  head  of  which  is  al- 
most always  surrounded  with  luminous  rays,  is 
no  larger  than  life.  It  may  be  readily  conceived 
that  such  apparitions  gave  rise  to  the  quaint  le- 
gends heard  in  different  countries,  particularly  in 
mountainous  regions  where  the  lofty  summits, 
crowned  with  clouds  of  varying  outline  and  ever- 
changing  colors,  have  played  so  grand  a  part  in 
the  composition  of  religious  fables. 

When  the  sun  is  just  at  the  horizon,  one  may, 


58  METEORS   AND   METEORIC   PHENOMENA. 

if  standing  close  to  a  railway,  see  the  shadows  of 
the  telegraph-posts  appear  on  the  long  pennant  of 
white  steam  that  rises  from  the  locomotive,  and 
floats  over  the  train.  Aeronauts  often  see  the 
magnified  image  of  their  balloon  upon  the  clouds, 
in  the  elevated  regions  through  which  they  pass. 
The  phenomenon  is  in  every  case  of  the  same  gen- 
eral nature  as  the  famous  Spectre  of  the  Brocken. 

THE  SHADOW  OF  MONT  BLANC. 

When  the  spectator  happens  to  be  standing  on 
the  summit  of  a  very  high  mountain,  the  shadow 
projected  by  the  setting  sun  is  directed  upward 
to  the  sky,  and  sometimes  produces  a  magnificent 
phenomenon,  which  was  observed  by  Messrs. 
Bravais  and  Martins  in  one  of  their  scientific 
excursions  to  Mont  Blanc.  M.  Bravais  has 
given  the  following  description  of  it : 

"  As  the  sun  Was  approaching  the  moment  of 
his  setting,  we  looked  in  the  direction  opposite  to 
the  luminary,  and  beheld,  not  without  some  sur- 
prise, the  shadow  of  Mont  Blanc  defined  upon  the 
snow-clad  mountains  in  the  eastern  part  of  the 
panorama  before  us.  It  gradually  rose  in  the  at- 
mosphere until  it  attained  the  height  of  an  entire 
degree,  remaining  all  the  while  distinctly  visible. 

"  The  air  above  the  apex  of  the  shadow  was 


THE  SHADOW  OF  MONT  BLANC.        59 

tinged  with  that  purply  rose-color,  which  one  sees, 
in  fine  sunsets,  suffusing  the  loftiest  peaks.  The 
edge  of  this  color  presented  a  zone  of  deeper  in- 
tensity, and  that  continuous  bordering  enhanced 
the  splendor  of  the  phenomenon. 

"  Let  any  one  imagine  the  mountains  in  the 
great  valley  of  Aosta  projecting  their  shadows  at 
one  and  the  same  moment  upon  the  atmosphere, 
the  lower  part  dark  with  a  slight  greenish  tinge, 
and,  above  each  of  these  shadows,  a  breadth  of 
purply  rose-color,  with  a  belt  of  deep  rosy-red  sep- 
arating it  from  them ;  let  him  add  to  that  the 
sharp  uprightness  of  the  cones  and  peaks  in  the 
shadow,  especially  of  their  uppermost  ridges,  and, 
finally,  the  effects  of  perspective,  making  all  these 
lines  converge  one  upon  the  other  toward  the 
very  summit  of  the  shadow  of  Mont  Blanc,  that  is 
to  say,  toward  that  point  in  the  sky  where  the 
shadows  of  our  bodies  should  be.  Even  then  he 
will  have  but  an  incomplete  idea  of  the  richness 
of  the  meteorological  phenomenon  that  developed 
itself  before  us  for  some  moments.  It  seemed  as 
though  an  invisible  being  were  in  a  throne  girt 
round  with  fire,  and  that,  on  their  knees,  angels 
with  glittering  wings  were  worshipping  him,  all 
bending  their  forms  toward  him.  At  the  sight  of 
a  spectacle  so  magnificent  our  arms  and  those  of 


60  METEOKS   AND   METEORIC   PHENOMENA. 

our  guides  dropped  motionless,  and  cries  of  enthu- 
siasm escaped  our  lips.  I  have  seen  the  superb 
aurora  borealis  of  the  north,  with  its  crowns  in 
the  zenith,  and  its  variegated  wavering  colon- 
nades of  pillars,  far  surpassing  the  finest  devices 
of  our  pyrotechnists,  but  the  spectacle  presented 
by  the  shadow  of  Mont  Blanc,  in  my  opinion, 
went  beyond  them  all." 


CHAPTER  III. 


BAIN,  SNOW,  AND  HAIL. 


Dew.— White  Frost.— The  Distribution  of  Rain  on  the  Surface  of  tho 
Globe.— The  Great  Rains  of  India.— Regions  without  Rain.— Influ- 
ence of  Forests.— The  Softening  of  Climates — Forms  of  the  Snow.— 
Flowers  under  the  Snow.— Glaciers  and  Rivers.— Hail. 


DEW   AND   WHITE   FROST. 

DEW — the  bright  deposit  of  limpid  little  drops 
which  glisten  in  the  morning  light  on  the  foliage, 
like  pearls  and  diamonds — is  caused  by  the  con- 
densation of  atmospheric  vapor  on  substances  suf- 
ficiently cooled  during  the  night  by  radiation,  or 
the  loss  of  heat  through  the  air.  Doctor  Wells, 
an  English  physician,  was  the  first  to  give  this  ex- 
planation, after  a  great  number  of  experiments. 

A  lock  of  very  dry  wool  weighing  10  grains, 
placed  upon  a  plank  sustained  by  four  uprights, 
increased  its  weight  only  two  grains  by  moisture, 
while  a  similar  lock  placed  above  it  gained  14: 
grains,  and  another,  laid  on  the  grass,  increased 


b2  METEORS   AND   METEORIC   PHENOMENA. 

16  grains.  Thermometers  substituted  for  these 
locks  of  wool  exhibited  the  lowest  range  where  the 
dew  fell  the  most  copiously.  On  the  other  hand, 
substances  that  do  not  so  readily  part  with  their 
caloric,  such  as  the  metals,  remained  dry,  while 
others  of  greater  radiating  power  lying  close  be- 
side them  were  covered  with  dew.  A  clear  sky 
was  found  to  be  favorable  to  the  cooling  process, 
and  consequently  to  the  deposit  of  dew ;  and  the 
passing  of  a  cloud,  which  gives  heat  for  heat,  was 
sufficient  to  arrest  the  phenomenon.  Moreover,  it 
was  observed  that  less  dew  formed  in  the  depth 
of  valleys  than  on  the  tops  of  hills,  from  which  a 
greater  extent  of  clear  sky  could  be  perceived. 

When  the  nocturnal  radiation  causes  the  tem- 
perature of  a  body  to  descend  below  zero,  the 
watery  vapor  condenses  into  ice,  and  white  frost 
is  deposited  instead  of  dew.  A  custom  prevalent 
in  India  may  serve  to  give  an  idea  of  the  power 
of  this  cooling  process.  Ice  is  habitually  procured 
there  by  exposing  shallow  pails,  filled  with  water, 
and  isolated  from  the  terrestrial  heat  by  layers  of 
loose  straw  laid  beneath  them,  in  some  open 
place,  during  very  clear  nights.  Under  these 
conditions  the  temperature  of  water  has  been 
known  to  fall  VI  degrees. 

In  order  to  protect  plants  from  the  disastrous 


DISTRIBUTION   OF   KAIN   ON   THE   GLOBE.  63 

effects  of  these  frosts,  it  suffices  to  arrange  a  hor- 
izontal screen  about  two  yards  above  the  ground, 
to  prevent  radiation.  In  the  open  field,  during  the 
clear  nights  of  the  end  of  April  and  the  beginning 
of  May,  the  cold  often  destroys  the  buds  of  plants. 
This  occurs  when  the  moon  shines  in  an  uncloud- 
ed sky,  but,  should  the  latter  be  obscured,  no  such 
bad  effects  are  observed. 

The  russet  or  "  red  moon  "  is  thus  explained  : 
The  luminary  of  night  is  often  most  wrongfully 
blamed  by  country-people,  since  it  is  really  the 
serenity  of  the  sky  which  is  the  cause  of  the  hurt- 
ful chill,  and  the  consequent  loss  of  crops. 

THE    DISTRIBUTION     OF    RAIN    ON    THE    GLOBED 
SURFACE. 

The  refreshing  stimulus  extended  to  plants  by 
fogs  and  dew  is  but  temporary.  A  humidity 
much  more  abundant  is  required  by  them.  Al- 
though there  are  very  heavy  dews  in  Egypt,  the 
vegetation  of  that  country  would  soon  disappear 
were  it  not  that  the  inundations  of  the  Mle  make 
up  for  the  extreme  rarity  of  rain.  In  years  when 
the  overflow  is  but  limited,  those  districts  which 
it  does  not  touch  remain  sterile.  Farmers  every- 
where, whether  fearing  an  excess  of  moisture  or 
of  drought,  attach  great  importance  to  the  rain, 


64:  METEOKS   AND   METEORIC   PHENOMENA. 

its  quantity  and  its  distribution  throughout  the 
seasons  of  the  year. 

Rain  falls  sometimes  when  no  cloud  is  visible, 
and  the  sky  is  perfectly  clear.  Various  observa- 
tions of  this  nature  are  cited  by  Humboldt  and 
Arago.  "  The  night  was  fine,"  says  a  savant  of 
Geneva,  "  and  the  stars  were  shining  with  their 
ordinary  brightness,  when  a  rain  composed  of 
large,  tepid  drops  fell  over  the  city  for  six  min- 
utes." The  same  phenomenon  is  reported  by  an 
eye-witness  to  have  taken  place  at  Constantine  at 
noon,  and  with  the  sky  magnificently  blue  and 
clear. 

But  usually  it  is  after  having  passed  through 
the  cloudy  form  that  the  moisture  of  the  atmos- 
phere precipitates  itself,  and  the  indications  con- 
tained in  the  preceding  chapter  give  the  first  ele- 
ments of  the  geographical  distribution  of  rain. 

To  commence  with,  we  have  the  equatorial 
zone,  enveloped  in  its  girdle  of  clouds,  formed  not 
only  by  the  vapors  arising  from  the  warm  waters 
of  the  ocean  carried  up  by  powerful  ascending 
currents,  but  also  by  those  that  the  trade-winds 
sweep  thither  from  north  and  south.  This  is  a 
region  where  rain  falls  every  day  and  in  great 
abundance,  the  mixture  of  the  masses  of  saturated 
air  with  the  cold  atmospheric  layers  taking  place 


DISTEIBUTION   OF   BAIN   ON  THE   GLOBE.  65 

continually  under  a  very  hot  sun.  Mention  has 
been  made  of  calms  sufficiently  prolonged  and  ac- 
companied by  rains  heavy  enough  to  make  the 
water  fresh  on  the  surface  of  the  sea.  The  mar- 
iner is  shy  of  these  latitudes,  where  the  tepid  and 
heavy  atmosphere  causes  an  irresistible  languor 
and  develops  dangerous  diseases.  Storms  are  so 
frequent  there  that  it  is  rarely  one  does  not  hear 
the  thunder  rumbling  above  the  dense  clouds  with 
an  echo  like  the  fiercest  electric  explosions  among 
mountains.  The  familiar  expression  Hacking-pot, 
so  often  on  the  lips  of  sailors,  very  appropriately 
conveys  the  effect  of  the  sombre  belt  thus  de- 
scribed after  the  unvarying  blue  of  the  trade- wind 
skies. 

All  the  vapor  disengaged  in  this  immense 
equatorial  boiler  does  not  fall  in  rain  at  the  same 
place.  Atmospheric  currents  higher  up  than  the 
trade- winds  carry  it  toward  the  two  poles.  They 
come  in  contact  with  the  surface  of  the  earth  in  a 
region  the  limits  of  which  vary  with  the  annual 
advance  of  the  sun,  like  those  of  the  equatorial 
belt  of  clouds,  and  which,  as  a  general  thing,  is 
fixed  in  the  tropics.  Places  situated  in  this 
region  have  periodical  rainy  seasons  called  win- 
terings. 

In  our  temperate  latitudes,  the  commingling 


66  METEOKS   AND   METEOEIC   PHENOMENA. 

of  layers  which  produces  the  rain  ceases  to  be  the 
result  of  ascending  currents  meeting  with  the 
upper  cold  air.  It  is  produced  by  horizontal  cur- 
rents, the  direction  of  which  is  generally  opposite 
to  each  other.  This  rain  falls  at  all  periods  of 
the  year. 

At  the  60th  degree  of  latitude  we  reach  the 
circumpolar  zone,  where  no  rain  falls  in  winter, 
owing  to  the  extreme  rarefaction  of  the  limpid 
atmosphere,  which  extends  over  the  immense  ex- 
panse of  snow,  and  no  fogs  are  seen  to  form,  ex- 
cepting in  those  regions  where  the  water  is  open. 

If  we  compare  the  system  of  the  circulation 
of  the  waters  upon  the  surface  of  the  globe  to  an 
alembic  with  the  fire  at  the  equator,  we  shall  see 
that  the  regions  outside  of  the  tropics  perform  the 
part  of  condensers.  Lieutenant  Maury  has  very 
strikingly  illustrated  the  functions  of  this  admira- 
ble apparatus.  "  The  average  amount  of  rain  that 
falls  annually  upon  the  surface  of  our  globe,"  he 
says,  "has  been  estimated  at  1.5  yards  in  depth  ; 
Thus,  then,  to  raise  enough  of  water  from  the 
ocean,  every  year,  in  the  form  of  vapor,  to  cover 
the  earth  with  a  spherical  coating  1.5  yards  deep  ; 
to  carry  that  watery  vapor  from  one  zone  to 
another,  and  then  to  precipitate  it  in  different 
forms  at  certain  determinate  points  at  chosen 


THE   GREAT   BAINS   OF   INDIA.  67 

epochs,  and  in  appropriate  quantities,  such  are 
the  functions  of  the  great  atmospheric  machine. 
The  water  vaporized  in  this  manner  being  taken 
principally  from  the  torrid  zone,  the  atmosphere 
in  that  zone  alone  must  absorb  a  liquid  mass  of 
nearly  5  yards  in  thickness,  and  3,000  marine  miles 
in  breadth,  upon  a  development  of  24,000  miles ; 
raise  it  as  high  as  the  clouds,  and  then  let  it  fall 
again  upon  the  earth.  This  it  must,  moreover, 
do  every  year  !  What  a  wondrous  and  powerful 
mechanism,  then,  is  this  atmosphere  of  ours,  and 
how  harmoniously  its  different  elements  must  be 
combined  in  order  that  this  work,  which  over- 
whelms the  imagination,  may  be  carried  on  with- 
out the  slightest  disarrangement  ever  manifesting 
itself  in  a  totality  of  functions  as  complex  as  they 
are  varied !  " 

THE   GKEAT   BAINS   OF   INDIA. 

The  regions  where  the  monsoons  prevail  have 
an  exceptional  pluvial  arrangement.  In  the  month 
of  April,  the  season  of  the  northeast  trade- winds 
closes  in  India.  The  vast  deserts  of  Central  Asia, 
heated  by  the  sun,  give  a  sort  of  breathing  aspira- 
tion that  produces  the  southwest  monsoons.  La- 
den with  the  vapors  of  the  ocean  and  of  the  Ara- 
bian Gulf,  these  winds  strike  the  Ghaut  range  of 


68  METEORS    AND   METEORIC    PHENOMENA. 

mountains  at  right  angles,  and  there  deposit  an 
extraordinary  quantity  of  rain,  which  Johnson  tells 
us  has  been  known  to  attain  the  enormous  meas- 
urement of  14i  inches  in  a  single  day.  They 
then  diverge  toward  the  Himalayas,  where  the 
temperature  is  lower  than  on  the  summits  of  the 
Ghauts.  There  they  abandon  in  the  form  of  snow 
and  rain  nearly  all  the  moisture  with  which  they 
were  charged,  and  thus  it  happens  that,  when  they 
reach  the  arid  wastes  beyond  those  mountains, 
they  rarely  have  enough  vapor  left  to  form  clouds. 
It  is  at  Cherrapondschi,  among  the  Himalayas, 
that  the  maximum  of  rain-fall,  viz.,  17  yards  per 
annum,  has  been  found  for  the  entire  globe. 

Owing  to  these  rains,  vegetation  attains  a 
prodigious  development  in  India ;  but  they  are 
accompanied  by  all  sorts  of  pests,  as  Mr.  D.  War- 
ren graphically  describes  them  in  his  work  on 
British  India. 

"A  suffocating  calm,"  he  says,  "which  pre- 
vails particularly  about  the  end  of  the  great 
heats,  precedes  the  setting  in  of  the  southern  mon- 
soon. With  the  end  of  May  come  on  the  first 
storms,  which  are  brief,  but  of  extreme  violence. 
Thunder  is  heard  in  the  distance  at  intervals ;  the 
sun  sets  in  a  bed  of  clouds,  and  every  evening 
the  lightnings  illuminate  all  points  of  the  horizon. 


THE   GREAT   RAINS   OF   INDIA.  69 

The  rain  falls,  for  half  an  hour,  in  torrents ;  after 
a  few  days  it  lasts  longer,  and  toward  the  middle 
of  June  it  rules  the  entire  day,  for,  when  it  is 
not  actually  raining,  the  sky  is  at  least  covered 
with  a  dense  and  threatening  curtain  of  clouds. 
It  rains  sometimes,  particularly  in  July,  for  thirty 
or  forty  hours  consecutively,  and  then  not  in  fine 
lines,  broken  and  almost  imperceptible,  as  in  our 
climates,  but  in  straight,  parallel  streaks,  and 
frequently  like  a  sheet  of  water  coming  down  all 
at  once  with  the  fury  and  impetuosity  of  a  cas- 
cade. 

"  The  miserable  clay-huts  of  the  natives  become 
thoroughly  soaked  under  this  continual  avalanche ; 
their  roofs  fall  in  and  bury  them,  or,  at  all  events, 
escaping  that  easier  fate,  they  find  themselves  ex- 
posed to  all  the  rigors  of  the  open  air,  and  perish 
in  great  numbers.  This  is  the  period  of  wide- 
spread distress,  which  does  not  spare  even  the 
nabob  and  the  conqueror ;  and  the  very  reptiles, 
those  of  the  most  hateful  species,  like  the  rest,  in- 
undated in  their  holes,  dart  to  the  surface  of  the 
soil  and  seek  an  asylum  among  the  dwellings  of 
men.  Numerous  varieties  of  snakes,  centipedes, 
and  scorpions,  climb  your  stairs,  invade  your 
houses,  and  glide  into  every  room.  It  is  impossi- 
ble to  take  a  step  in  one's  bedchamber  at  night 


70  METEOE8    AND   METEORIC   PHENOMENA. 

without  a  light,  unless  one  is  prepared  to  run  the 
risk  of  a  sting  that  may  prove  fatal.  The  utmost 
distrust  must  be  felt  of  every  thing  that  one  touch- 
es ;  a  cruel  bite  may  kill  you  from  the  inside  of  a 
boot  or  a  sleeve.  For  some  time  you  lead  a  life 
of  continual  alarm  and  disgusting  contacts;  but 
these  annoyances  are  not  of  long  duration.  The 
monsoon  begins  to  decline  in  the  month  of  Au- 
gust, and  dies  away  in  the  first  days  of  Septem- 
ber. The  five  months  that  follow,  until  the  be- 
ginning of  February,  are  delicious,  and  make  one 
forget  those  that  went  before ;  there  is  rapture  in 
the  mere  fact  of  existence,  the  air  is  so  fresh  and 
the  face  of  Nature  so  lovely." 

REGIONS   WITHOUT  BAIN. 

There  are  parts  of  the  globe's  surface  where 
rain  is  almost  unknown.  Such  are  the  coasts  of 
Peru,  and  it  is  easy  to  discover  the  reason.  They 
lie  within  the  sweep  of  the  southeast  trade- 
winds.  The  latter  traverse  the  Atlantic  and 
there  become  laden  with  vapors,  which  they  then 
deposit  on  their  trip  across  the  American  Conti- 
nent, where  the  rain  feeds  the  sources  of  the  Rio 
de  la  Plata  and  the  southern  affluents  of%  the 
Amazon.  Then,  they  pass  on  to  the  snowy 
peaks  of  the  Cordilleras,  where  the  low  tempera- 


REGIONS   WITHOUT  RAIN.  71 

ture  completely  divests  them  of  tlie  moisture  they 
may  still  have  retained.  We  need  not  be  sur- 
prised, then,  that  they  are  dry  and  cold  when 
they  sweep  down  the  western  slope  of  the  Andes, 
and  remain  so  until  they  meet  the  waters  of  the 
Pacific  Ocean. 

A  large  part  of  Australia  also  is  in  the  track 
of  the  southeast  trade-winds,  and  should  have 
large  rivers,  like  that  intertropical  portion  of 
South  America  just  mentioned;  but  the  contrary 
is  the  case.  Maury  explains  this  difference  by 
the  relations  that  exist  between  the  direction 
of  the  winds  and  that  of  the  coasts.  "  In  Aus- 
tralia," he  says,  "  the  eastern  coast  runs  in  the 
direction  of  the  trade-winds,  while  in  South 
America  it  is  perpendicular  to  that  line.  Conse- 
quently, in  Australia,  these  winds  only  fringe  the 
coast,  so  to  speak,  with  their  vapors,  and  dis- 
pense their  rains  over  these  parched  lands  so 
sparingly,  that  the  trees,  in  order  to  retain  the 
small  amount  of  moisture  allotted  to  them,  are 
obliged  to  arrange  their  leaves  in  the  same  line 
as  the  rays  of  the  sun,  since,  if  they  were  in  the 
natural  position,  they  would  be  too  quickly  dried 
up.  On  the  contrary,  in  South  America,  where 
the  winds  blow  in  a  direction  perpendicular  to 
the  shore,  and  cause  the  humidity  with  which 


72  METEOES   AND   METEORIC    PHENOMENA. 

they  are  charged  to  penetrate  to  the  heart  of  the 
country,  one  sees  the  leaves  striving,  as  it  were, 
to  reach  the  sun's  rays  and  present  themselves  to 
them  in  their  fullest  development." 

The  Desert  of  Sahara,  situated  in  the  domain 
of  the  trade-winds  that  cross  the  land  only,  is  de- 
nied rain  entirely,  and  shows  us  what  our  globe 
would  be  without  the  magnificent  reservoir  of 
the  ocean.  From  the  immense  sandy  plains  of 
Africa  there  rises  only  a  column  of  burning  air, 
while  not  even  a  drop  of  dew  falls  to  moisten  the 
parched  surface  and  there  develop  vegetation. 

THE   INFLUENCE   OF   FORESTS. 

The  influence  of  forests,  in  reference  to  rain, 
has  been  established  by  numerous  observations. 
Columbus  mentions  it  in  his  "Journal  of  the 
Yoyage  to  America,"  where  he  attributes  to  the 
density  and  extent  of  the  forests  that  covered  the 
mountain-sides  the  abundance  of  rain  to  which 
he  was  so  long  exposed  while  coasting  along  the 
shores  of  Jamaica.  He  remarks  that  "formerly 
rain  was  no  less  abundant  at  Madeira  and  on 
the  Canaries  and  Azores,  but  since  the  trees  that 
gave  shade  have  been  cut  down,  it  has  become 
much  less  frequent  in  those  countries." 

Humboldt  demonstrates   that   there   exists   a 


THE  INFLUENCE   OF   FORESTS.  73 

frigorific  radiation  above  wooded  regions,  that 
must  condense  the  vapors.  The  summits  of 
mountains  covered  with  forests  become  enveloped 
with  mists  oftener  than  those  of  mountains  that 
are  bare,  and  springs  of  water  are  more  frequent- 
ly found  among  them.  Numerous  plantations  of 
trees  in  Egypt  have  caused  the  rains  that  had 
totally  ceased  to  reappear — a  fact  that  deserves 
especial  mention.  In  some  parts  of  the  Antilles 
the  clearing  of  portions  of  the  soil  has  diminished 
the  quantity  of  rain,  and  the  watercourses  have 
lost  their  abundance. 

At  Porto  Rico  a  different  plan  has  been  pur- 
sued. A  decree  of  the  King  of  Spain  prescribed 
that,  every  time  a  tree  should  be  cut  down,  three 
should  be  planted  for  it,  and  the  country  has  con- 
sequently retained  its  high  fertility.  The  beauty 
of  the  soil  and  the  abundance  of  water  have  left 
the  land  more  productive  than  on  the  adjacent 
islands. 

We  extract  from  the  scientific  work  of  M. 
Boussingault  a  passage  confirming  the  existence 
of  similar  relations  between  the  clearing  away 
of  the  woods  and  the  quantity  of  water:  "In 
the  valley  of  Cauca,"  he  says,  "  it  is  well  known 
that  such  and  such  a  district,  whose  soil  and  me- 
dium temperature  are  favorable  to  the  cultivation 


74:  METEOKS   AND  METEORIC   PHENOMENA. 

of  the  cacao-tree,  still  gives  no  good  result  if  the 
latter  be  placed  too  near  to  the  forest.  But,  when 
these  forest-lands  are  cleared,  and  transformed  to 
fields  of  yucca,  sugar-cane,  and  maize,  the  cacao- 
tree  flourishes  remarkably.  The  following  fact 
was  obtained  from  Don  Sebastian  Marisansena,  a 
resident  of  Cartago.  Having  procured  the  title 
of  capitan  poblador  to  found  a  village  at  La 
Balsa,  at  the  foot  of  the  Quindin  range,  he  began 
by  putting  in  a  plantation  of  cocoa-trees.  Dur- 
ing the  first  ten  years  the  crops  amounted  to 
little  or  nothing,  because  the  rains  were  too  fre- 
quent. The  hacienda,  or  farm,  began  to  be  pro- 
ductive only  when  the  inhabitants  of  La  Balsd 
were  numerous  enough  to  make  the  clearings  ex- 
tensive. Then  at  length  the  sun  could  ripen  the 
cacao.  In  1816,  political  events  led  to  a  large 
emigration  of  the  people,  only  the  negroes  re- 
maining on  the  farm.  Six  years  later,  the  sur- 
rounding fields  were  again  transformed  to  forests ; 
the  crops  diminished  more  and  more,  and  in 
182T,  when  I  passed  through  La  Balsd,  they  had 
not  gathered  any  cacao  for  three  years." 

AMELIORATION   OF   CLIMATE. 

The  clouds  when  they  dissolve  in  rain  restore 
to  the  atmosphere  all  the  heat  that  was  taken  up 


AMELIORATION   OF   CLIMATE.  75 

in  forming  them.  Every  one  may  have  observed 
the  increased  mildness  of  the  atmosphere  after  a 
shower  of  some  duration.  This  circumstance 
powerfully  affects  the  climates  of  the  higher  lati- 
tudes, especially  in  the  southern  hemisphere,  where 
the  counter  trade-winds  of  the  northwest  con- 
dense their  abundant  vapors.  It  has  been  ob- 
served that,  relatively  to  their  position,  the  south- 
ern Shetlands  have  no  very  cold  winters ;  a  fact 
undoubtedly  due  to  the  great  quantity  of  heat 
disengaged  during  the  rains. 

The  quantity  of  rain  that  falls  on  the  western 
slope  of  the  Patagonian  Andes  (and,  according  to 
Admiral  Fitzroy,  it  amounts  to  more  than  four 
yards  in  forty  days)  imparts  a  remarkable  degree 
of  heat  to  the  winds  that  descend  upon  the  other 
slope.  It  is  to  them,  as  well  as  to  a  feeble  oce- 
anic current,  that  the  extraordinary  climate  of  the 
Falkland  Islands  is  to  be  attributed.  These  isl- 
ands are  in  a  latitude  corresponding  to  the  rude 
regions  of  Labrador,  and  yet  cattle  pass  the  winter 
there  in  the  midst  of  fine  pasture. 

In  North  America,  at  the  base  and  on  the 
slopes  of  the  Rocky  Mountains,  where  the  Mis- 
souri takes  its  rise,  there  is  a  phenomenon  ob- 
servable that  must  be  ascribed  to  the  heat  disen- 
gaged by  the  great  condensation  that  takes  place 


76  METEORS   AND   METEORIC    PHENOMENA. 

when  the  western  winds  of  the  Pacific  strike  the 
summits  of  the  chain.  In  winter,  navigation  is 
open  on  the  upper  part  of  the  river,  while  lower 
down  it  is  entirely  closed  by  the  ice.  At  a  very 
considerable  elevation,  a  spring  temperature  is 
enjoyed,  and  the  country  is  covered  with  rich 
verdure,  at  the  very  moment  when  the  severest 
cold  prevails  in  the  distant  plains  below. 

FORMS    OF   THE    SNOW. 

When  a  current  of  very  cold  air  penetrates 
to  a  warm  apartment  suddenly,  it  may  produce 
snow,  if  the  room  be  full  of  watery  vapor.  The 
story  is  told  that,  upon  one  occasion  in  St.  Peters- 
burg, a  pane  of  glass  was  accidentally  broken  in 
the  window  of  a  saloon  where  a  large  party  was 
assembled,  and  a  gust  of  wind  bursting  in  through 
the  orifice,  congealed  the  vapors  of  the  room  and 
scattered  them  over  the  astonished  guests  in  the 
shape  of  snow-flakes.  Similar  effects  have  been 
noticed  in  Siberia  and  Nova  Zembla. 

Whenever  the  temperature  of  the  clouds  falls 
below  zero,  their  drops  congeal  and  form  snow, 
which  then  falls  through  the  air  in  flakes  until  it 
strikes  the  ground.  These  flakes,  when  caught 
upon  a  black  surface  and  examined  through  the 
microscope,  exhibit  a  remarkable  regularity  of 


FOKMS    OF    THE    SNOW.  77 

form  that  long  since  attracted  the  attention  of 
observers.  Kepler  speaks  of  their  structure  with 
lively  admiration,  and,  since  his  day,  these  grace- 
ful crystallizations  have  been  described  with  care. 


FORMS   OF    SNOW-CRYSTALS. 


Yet,  notwithstanding  their  great  variety,  they  de- 
pend upon  extremely  simple  laws.  "  These  snow 
crystals,"  says  Tyndall,  "being  formed  in  a  calm 


78  METEORS    AND   METEORIC    PHENOMENA. 

atmosphere,  are  constructed  on  the  same  model : 
their  molecules  group  together  to  form  hexagonal 
stars.  From  a  central  nucleus  project  six  needles 
that,  together,  form  an  angle  of  60  degrees.  From 
these  central  needles  there  shoot  out  other  small- 
er ones  to  the  right  and  the  left,  in  their  turn  de- 
scribing with  infallible  fidelity  their  angle  of  60 
degrees.  These  six-leaved  flowers  assume  the 
most  varied  and  wondrous  forms.  They  are  pat- 
terned in  the  finest  gauzy  films,  and  all  around 
their  angles  are  sometimes  seen  rosettes  of  still 
more  microscopic  dimensions.  Beauty  superadds 
itself  to  beauty,  as  though,  when  once  at  work, 
Nature  took  pleasure  in  showing,  even  in  the  nar- 
rowest sphere,  the  omnipotence  of  her  resources." 
The  temperature,  the  humidity,  the  degree  of 
motion  in  the  air,  modify  these  crystallized  fig- 
ures. Flakes  that  fall  at  the  same  time  generally 
have  the  same  shape ;  but,  when  there  is  an  in- 
terval between  the  falls,  a  new  variety  is  found 
each  time. 

FLOWERS    UNDER   THE    SNOW. 

In  years  when  the  snow  has  remained  long 
upon  the  ground,  the  watercourses  are  more 
abundant,  and  the  harvests  more  certain.  Win- 
ters at  the  North  without  snow  are  calamities 


FLOWERS    UNDER   THE    SNOW.  79 

equalled  only  by  springs  at  the  South  without 
rain.  Snow  acts  as  a  covering,  or  screen,  which, 
in  sheltering  the  soil,  prevents  it  from  being 
thoroughly  congealed,  by  the  radiation  of  all  its 
caloric  into  space,  in  clear,  cold  nights ;  and  then, 
when  the  thaw  comes,  it  fully  saturates  the 
ground. 

Between  the  eternal  snows  that  cover  the  tops 
of  the  Pyrenees  and  the  Alps,  and  the  slopes  at 
their  foot,  where  the  vine  flourishes,  there  is  a 
region  in  which  the  snow  melts  at  different  sea- 
sons, according  to  its  elevation ;  but,  in  all  places, 
even  at  great  heights,  where  it  remains  for  six  or 
eight  months,  when  it  does  disappear  it  leaves  the 
soil  covered  with  rich  herbage  that  vegetated  un- 
der its  shelter,  and  that  offers  an  abundant  pas- 
ture to  the  flocks  and  herds.  The  green  sward 
thus  strengthened  is  immediately  enamelled  with 
a  multitude  of  lovely  flowers  that  had  budded  be- 
neath the  snow.  The  attempt  had  often  been 
made,  but  in  vain,  to  acclimate  these  Alpine 
plants  in  our  gardens,  when  a  florist  conceived 
the  idea,  which  seemed  odd  enough  at  first,  to 
place  them,  during  the  winter,  between  the  orange 
and  pomegranate  trees  in  his  hot-house.  The 
hardy  plants  brought  from  a  rude  region,  where 
the  climate  is  similar  to  that  of  Siberia,  and  where 


80  METEORS    AMD   METEORIC    PHENOMENA. 

the  mercury  sinks  to  30°  below  zero,  were  per- 
fectly preserved  by  the  process.  This  was  be- 
cause they  found  in  the  hot-house  the  conditions 
provided  for  them  by  the  thick  covering  of  snow 
that  shielded  them  in  their  natural  haunts.  By 
its  diminutive  conducting  power,  the  covering  in 
question  shelters  them  from  cold,  and,  above  all, 
from  those  abrupt  changes  of  temperature  that 
are  so  injurious  to  frail  organizations.  By  anal- 
ogy we  may  infer  how  grain  is  protected  by  the 
snow  in  the  furrows  of  our  fields. 

GLACIERS   AND   RIVERS. 

An  admirable  arrangement  in  the  glaciers  of 
the  Alps  has  been  made  apparent  by  a  series  of 
observations,  carefully  pursued  for  several  years 
consecutively,  in  regard  to  the  mean  depth  of 
water  in  the  rivers  flowing  from  them,  in  each 
month  of  the  year.  "  Since  much  less  rain  falls 
in  summer  than  in  other  seasons,"  says  Jean 
Reynaud,  "  and  since  it  evaporates  again  almost 
immediately,  all  the  small  streams  diminish  in 
volume,  and  some  are  even  dried  up  altogether ; 
thus,  at  last,  the  main  watercourses  do  not  re- 
ceive from  their  tributaries  sufficient  aliment  to 
sustain  them.  But  Nature  has  arranged  a  pecu- 
liar class  of  tributaries  for  rivers  important  enough 


GLACIERS    AND   RIVERS.  81 

to  require  such  special  provision,  and  these  yield 
them  all  the  more  in  proportion  as  their  ordinary 
resources  diminish,  and  vice  versa.  These  are  the 
streamlets  that  flow  from  the  glaciers ;  and  the 
immensity  of  the  process  required  to  supply  them 
will  be  comprehended  at  once,  when  we  reflect 
that  they  must  necessarily  be  raised  from  the 
mountains  above  the  clouds,  in  order  to  take  their 
rise  where  they  do.  None  but  regions  lifted  up 
to  those  prodigious  elevations  would  be  in  a  posi- 
tion to  accumulate  such  a  quantity  of  snow  and 
ice,  and  to  retain  enough  of  it  during  the  summer, 
allowing  it  to  melt,  little  by  little.  Thus,  the 
hotter  the  summer  and  the  more  extreme  the 
drought  in  the  watercourses  of  the  plains,  only  the 
more  rapidly  and  copiously  will  the  deposits  of 
ice  heaped  up  at  the  fountain-head  be  made  to 
melt.  Consequently  the  mountain-brooks  will  be 
the  fullest  at  the  very  moment  when  the  others 
will  be  most  completely  exhausted.  On  the  other 
hand,  in  spring  and  autumn,  when  the  abundance 
of  rain  causes  the  streamlets  of  the  valley  and  the 
plain  to  swell  in  every  direction,  and  tends  to 
raise  the  rivers  above  their  regular  beds,  the 
glaciers,  receiving  less  heat,  feed  the  rills  that 
flow  from  them  less  lavishly,  and  an  actual  dry- 
ness  results,  so  far  as  they  are  concerned,  which 


82  METEORS    AND   METEOEIC    PHENOMENA. 

counterbalances  the  humidity  of  the  regions  lower 
down.  The  general  result  is,  that  the  rivers  which 
are  subject  solely  to  the  influence  of  the  glaciers 
are  full  in  summer  and  shallow  in  winter  ;  while 
those  which  are  cut  off  from  all  connection  with 
the  reservoirs  of  the  high  regions,  and  are  depend- 
ent upon  the  rains  alone,  have  the  most  water  dur- 
ing the  cold  season  and  the  least  in  the  hot  months. 
Finally,  those  that  have  the  aid  of  both  the 
glaciers  and  the  rain,  at  different  times,  along 
with  ordinary  tributaries  and  such  as  flow  from 
the  high  mountains,  have,  other  things  being 
equal,  a  more  even  and  steady  supply  of  water 
than  the  rest." 

HAIL. 

Hail  is  a  shower  of  globules  of  ice,  the  size  of 
which  usually  varies  from  that  of  a  pea  to  that  of 
a  hickory-nut,  but  sometimes  attains  the  dimen- 
sions of  an  egg,  and  even  of  an  ordinary  apple. 
It  has  been  remarked  that  there  is  nearly  always 
a  little  accretion  of  spongy  snow  in  the  centre  of 
hailstones.  This  is  their  only  opaque  portion ; 
the  concentric  layers  that  surround  it  have  all  the 
transparency  of  ordinary  ice.  The  nucleus  and 
its  coverings  therefore  do  not  seem  to  be  formed 
in  the  same  manner*  Sometimes  there  fall  heavy 


HAIL.  S3 

hailstones  with  a  snowy  centre  which  are  com- 
posed of  rings  or  layers  alternately  transparent 
and  opaque.  The  fine  soft  hail  seen  in  autumn 
and  winter  particularly,  the  surface  of  which 
looks  as  though  powdered  with  flour,  is  usually 
called  sleet.  It  is,  properly  speaking,  a  kind  of 
middle  formation  between  hail  and  snow. 

Yolta  relates  that  one  night  in  the  month  of 
August,  1707,  he  picked  up,  during  a  storm  that 
burst  over  the  town  of  Como,  several  hailstones 
that  weighed  nearly  ten  ounces.  Darwin  men- 
tions a  tempest  on  the  pampas  of  South  America, 
where  the  icy  fragments  that  fell  were  so  heavy 
as  to  kill  large  animals. 

We  have  just  spoken  of  a  hailstorm  that  hap- 
pened during  the  night.  This  is  a  very  rare  oc- 
currence, for  it  is  usually  during  the  hottest  hours 
of  the  day  in  summer  that  hail  forms.  The 
clouds  that  contain  it  seem  to  have  great  depth, 
and  are  distinguished  from  other  storm-clouds  by 
their  ashy  color.  Their  edges  have  numerous 
jagged  indentations,  and  circular  movements  are 
sometimes  remarked  in  them.  Hail  usually  pre- 
cedes storms  of  rain,  and  sometimes  accompanies 
them  ;  but  it  scarcely  ever  follows  them,  especial- 
ly when  the  rains  have  lasted  for  any  time.  In 
the  tropics,  hailstorms  have  been  noticed  only  on 


84  METEOE8   AND   METEORIC   PHENOMENA. 

the  lofty  mountains.  None  falls  in  the  plains. 
It  is  more  particularly  frequent  in  the  temperate 
zone,  and  then  becomes  more  and  more  rare  as 
we  advance  toward  the  polar  regions. 

In  most  cases,  the  phenomenon  of  hail  has  a 
local  character.  It  is  very  frequent  at  the  outlet 
of  the  deep  valleys  of  the  Alps  and  upon  the 
lower  acclivities  that  separate  them  from  the 
plains.  The  low  lands  of  Borgo-franco,  near  the 
Yal  d' Aosta,  are  -scourged  by  it  every  year;  At 
Clermont,  at  the  foot  of  the  Puy-de-D6me,  hail 
falls  very  often,  while  on  the  heights,  half  a 
league  distant,  but  one  fall  of  hail  has  been  re- 
corded in  the  last  twenty-three  years!  Some- 
times there  are  great  storms  during  which  hail 
falls  over  a  vast  extent  of  territory,  but  these  are 
fortunately  rare. 

The  formation  of  hail  has  been  more  easily 
explained  since  the  discovery  by  aeronauts  of  very 
cold  atmospheric  layers  (the  thermometer  mark- 
ing 4:0°)  at  heights  comparatively  limited,  and 
that  too  in  midsummer.  These  layers,  as  we  have 
already  said,  are  filled  with  fine  needles  of  ice, 
which,  when  packed  together,  may  form  the  nu- 
cleus of  the  hailstones,  upon  which  the  vapors 
solidify  themselves  in  other  layers.  The  exist- 
ence of  whirlwinds,  arising  from  the  collision  of 


HAIL.  85 

opposite  currents — chiefly  equatorial  and  polar — 
explains  the  suspension  and  even  the  ascension, 
by  a  spiral  movement,  of  the  hailstones  that  form. 
Leaves  and  twigs,  torn  from  trees  by  a  tempest, 
have  been  seen  to  fall  at  a  distance,  covered  with 
a  coating  of  ice. 

The  currents  originated  by  these  whirlwinds 
are  generally  in  opposite  electrical  conditions  be- 
fore they  become  mingled.  Hence  it  is  remarked 
that  it  rarely  hails  without  thunder  being  heard, 
and  that  during  such  a  fall  the  electricity  de- 
veloped varies  not  only  in  degree  but  in  kind. 

Some  years  ago,  rows  of  long  poles  were 
planted  in  the  fields  in  France  to  serve  as  hail- 
rods,  or  protectors  against  the  hail.  They  were 
intended  to  modify  the  electrical  conditions  of  the 
atmosphere ;  but  the  system  was  found  to  fall 
short  of  the  purpose,  and  Arago,  in  arguing 
against  it  in  one  of  his  learned  "  Notices,"  advises 
farmers  to  give  more  of  their  attention  to  mutual 
cooperative  associations,  until  science  shall  have 
discovered  some  better  defence  against  the  rav- 
ages of  the  storm. 


CHAPTER   IV. 

PHENOMENA   OF  THE  GLACIERS. 


Meteorology  of  the  Glaciers.— Their  Formation.— The  Grindelwald  and 
Furca  Glaciers.  —  Amphitheatres.— Neves.— Moraines.— Movemen ts 
of  the  Glaciers.— Primitive  Glaciers.— Polar  Glaciers.— Variations  of 
the  Seasons  and  Climate. 


METEOROLOGY  OF  THE  GLACIERS. THEIR  FORMATION. 

WE  have  already  spoken  of  the  favorable  in- 
fluence of  glaciers  upon  the  mean  height  of  the 
watercourses  during  each  season.  In  a  remarka- 
ble note  appended  to  the  work  on  "  Meteorology," 
by  Kaemtz,  M.  Chas.  Martins,  one  of  the  most 
learned  professors  of  the  day,  summarily  examines 
the  influence  of  temperature  and  aqueous  meteors 
on  these  solid  rivers  that,  issuing  from  the  region 
of  external  snow,  descend  slowly  into  the  plains, 
in  the  midst  of  forests  and  cultivated  fields. 

"  If  we  examine  the  phenomena  presented  by 
the  glaciers,"  says  M.  Chas.  Martins,  "  in  a  pure- 
ly meteorological  point  of  view,  we  shall  see  that 


METEOEOLOGY   OF   THE   GLACIEES.  87 

it  is  not  too  rash  to  maintain  that  a  time  will 
come  when  we  shall  be  enabled  to  judge  the 
modifications  of  the  atmosphere  by  those  of  the 
glaciers,  and  vice  versa.  But  in  order  thus  to 
establish  in  a  positive  manner  the  link  that  unites 
the  meteorology  and  the  physical  exterior  of  the 
globe,  it  is  desirable  to  make  a  long  series  of 
meteorological  observations  in  the  vicinity  of  the 
glaciers,  so  as  to  bring  the  two  kinds  of  phenome- 
na into  direct  ra/pport" 

Before  making  known  some  of  the  modifica- 
tions indicated  in  this  passage,  we  must  pause  for 
a  brief  space  to  consider  the  formation  of  the 
glaciers.  This  is  the  point  of  departure  recom- 
mended by  M.  Martins  for  the  desired  observa- 
tions. 

When,  in  summer,  the  clouds  disperse,  after 
the  tempests  of  rain  that  fall  in  the  plains,  the 
summits  of  the  mountains  are  seen  whitened  with 
newly-fallen  snow,  which  melts  very  quickly  in 
the  sun,  but  remains  on  the  highest  peaks,  in  the 
region  of  eternal  snows,  as  low  down  as  a  certain 
limit  that  varies  according  to  the  country  and  the 
exposure.  This  limit,  when  traced  upon  an  ex- 
tended chain  of  mountains,  appears  to  be  almost 
horizontal ;  but,  at  certain  points  in  the  depth  of 
the  valleys,  the  glaciers  are  seen  descending  in  long 


88  METEORS    AND   METEORIC   PHENOMENA. 

white  trains  to  the  plain.  M.  George  Altmann, 
in  his  "  Treatise  on  the  Icy  Mountains  of  Switzer- 
land," has  given  the  following  description  of  the 
Grindelwald  glacier,  so  often  explored  by  natural- 
ists: 

THE    GRINDELWALD   AND   FURCA   GLACIERS. 

"  The  village  of  Grindelwald  is  situated  in  a 
long  and  narrow  gorge  of  the  mountains.  From, 
that  point  we  begin  to  get  a  glimpse  of  the 
glacier,  but,  in  order  to  see  it  in  its  full  extent, 
we  must  go  higher  up.  Then  one  of  the  finest 
spectacles  that  can  be  imagined  is  revealed.  It 
is  a  sea  of  ice,  or  an  immense  expanse  of  frozen 
water,  which  descends  into  the  valley  along  the 
slope  of  a  lofty  mountain.  From  this  frozen 
reservoir  starts  a  prodigious  mass  of  pyramids 
heaped  together,  forming  a  kind  of  curtain  that 
occupies  the  whole  breadth  of  the  valley,  an  ex- 
panse of  about  eight  hundred  yards,  and  is  bor- 
dered on  both  sides  by  lofty  mountains,  covered 
with  verdure  and  a  forest  of  pines  up  to  a  certain 
height.  This  accumulation  of  pyramidal  forms 
looks  like  a  sea  agitated  by  the  winds,  the  waves 
of  which  have  been  suddenly  congealed  by  the 
frost ;  or,  rather,  one  beholds  an  amphitheatre 
formed  by  an  immense  assemblage  of  icy  hillocks 


THE  GKINDELWALD  AND  FUECA  GLACIERS.        89 

of  a  bluish  color,  and  each  of  them  from  thirty  to 
forty  feet  in  height.  The  point  of  view  is  of 
marvellous  beauty.  Nothing  is  comparable  to  it, 
especially  when,  in  summer,  the  sun  darts  its  rays 
upon  this  group  of  glittering  pyramids.  Then  the 
entire  glacier  begins  to  smoke,  and  glows  with  a 
brightness  that  dazzles  the  eyes." 

We  will  add  to  this  description  the  account  of 
the  Furca  glacier  given  by  Coxe  in  his  "  Letters 
on  Switzerland  " : 

"  After  long  efforts  and  a  toilsome  march  over 
immense  stretches  of  snow  and  ice  that  came  in 
our  way,  with  precipices  and  torrents  constantly 
beneath  our  feet,  we  reached  the  upper  part  of  the 
valley  by  an  extremely  steep  ascent.  The  great 
number  of  forked  and  irregular  masses  of  rock 
which,  accumulated  around  this  valley,  stud  the 
summit  of  the  eminence,  have,  it  is  said,  originated 
the  name  now  given  it  of  the  Forks  or  Furca. 
The  region  in  which  we  then  were,  appeared 
more  frightful  and  desolate  than  even  the  most 
desert  parts  of  Saint  Gothard.  Below  us,  it  is 
true,  the  mountains  were  clad  in  rich  verdure,  and 
bestrewn  with  fragrant  flowers;  but  vegetation  did 
not  reach  to  the  height  where  we  were.  The 
most  savage  sterility  surrounded  us,  and  near  by 
there  rose  a  fearful  accumulation  of  ice,  from  which 


90  METEOKS   AND   METEOEIC   PHENOMENA. 

there  descended  a  cataract  that,  rolling  toward  the 
Yalais,  is  no  doubt  one  of  the  sources  of  the 
Rhone.  This  glacier  was  on  our  left  and  a  little 
above  us,  and  never  did  any  mass  of  objects,  how- 
ever grand  or  terrible,  present  to  us  a  combina- 
tion of  beauty  at  once  so  terrifying  and  so  sub- 
lime. 

"  From  that  point  we  descended  a  mass  of 
broken  rocks  which,  in  every  direction,  bristle  the 
ridges  of  a  long  line  of  precipices.  I  then  felt 
sufficiently  fatigued  to  require  rest  and  refresh- 
ment. We  seated  ourselves  on  the  banks  of  a 
very  limpid  streamlet  which  flowed  briskly  down 
the  mountain,  the  latter  being  so  steep  that  our 
little  repast  had  to  be  propped  to  prevent  it  from 
rolling  away  from  us.  Before  us  the  Furca  gla- 
cier lay  extended  in  all  its  beauty.  It  is  an  im- 
mense mass  of  ice  that  spreads  out,  in  the  form  of 
an  amphitheatre,  between  two  heaps  of  rocks  more 
jagged,  if  possible,  than  any  that  we  saw  in  the 
neighboring  mountains.  This  amphitheatre  en- 
tirely fills  the  precipice  that  separates  them,  and . 
rises  gradually  from  their  base  to  a  short  distance 
from  their  summits.  The  sun,  which  darted  its 
rays  perpendicularly  upon  the  glacier,  gave  it  the 
brightness  and  transparency  of  crystal,  while  the 
shadows  of  its  vast  fragments,  admirably  colored, 


CIRCLES,    NEVE,    ETC.  91 

intersected  its  dazzling  whiteness  with  all  the 
varying  tints  of  a  truly  celestial  blue.  Terrible 
cracking  noises,  indicative  of  new  crevices  form- 
ing in  the  glacier,  were  heard  several  times ;  and 
the  Rhone,  pouring  along  at  its  feet  in  the  form 
of  a  torrent,  mingled  its  continuous  roaring  with 
the  din.  It  is  in  a  great  measure  to  the  accumu- 
lation of  ice  that  I  have  just  described  that  the 
river  owes  its  existence." 

CIRCLES. NEVE. MORAINES. 

Ramond,  the  naturalist^  the  intrepid  explorer 
of  the  Alps  and  Pyrenees,  and  the  translator  of 
Coxe's  book,  has  added  to  his  translation  some  ex- 
cellent observations  on  the  glaciers,  and  has  been 
one  of  the  first  to  point  out  a  part  of  the  causes 
that  concur  in  their  formation  and  determine 
their  progress.  Before  him,  Haller,  De  Saussure, 
and  De  Luc,  had  already  established  a  number  of 
important  facts.  But  it  is  to  more  recent  re- 
searches that  we  owe  the  explanation  of  most  of 
the  phenomena  connected  with  the  nature  and 
movement  of  glaciers. 

"  Snow  accumulates  around  the  high  peaks  in 
deep  depressions  known  as  amphitheatres.  It  is 
in  descending  from  these  amphitheatres  toward 

the  valleys  that  the  snow  is  transformed,  under 
5 


92  METEORS    AND    METEOKIO   PHENOMENA. 

the  influence  of  the  sun  and  nocturnal  frosts,  tc 
small  grains  of  transparent  ice,  and  that  this 
granulated  mass,  called  neve  in  Switzerland,  be- 
comes converted,  by  pressure  and  successive  con- 
gelations, to  a  moving  mass  of  ice,  sometimes 
white  and  filled  with  bubbles  of  air,  and  some- 
times more  compact  and  skyey  blue." 

Such  is  the  origin  of  the  glaciers,  which  their 
own  weight  causes  to  advance  slowly  in  the  direc- 
tion of  the  declivities.  Huge  crevices  are  pro- 
duced during  this  movement,  and  the  water  that 
drips  down  into  them  when  the  snow  melts,  accel- 
erates it  by  hollowing  out  cavities  in  the  lower- 
most parts  of  the  mass.  Besides,  when  the  water 
thus  contained  in  the  glacier  dilates  by  a  new 
congealment,  the  entire  mass  increases  in  volume, 
and  extends  in  the  direction  where  it  finds  the 
least  resistance,  that  is  to  say,  from  the  higher 
point  to  the  lower.  This  continual  progression 
of  the  glaciers  has  been  proved  by  incontestable 
facts. 

A  bed  of  pebbles  and  sand  being  interposed 
between  the  bottom  of  the  glacier  and  the  rock, 
the  result  is,  that  the  action  of  the  masses  of  ice 
in  movement  polishes  the  surface  over  which  they 
descend,  and  makes  creases  and  furrows  running 
in  the  same  direction.  This  effect  has  been  well 


CIRCLES,   NEVE,   ETC.  93 

ascertained,  not  only  in  the  ice-caverns  that  are 
sometimes  found  at  the  extremities  of  the  glaciers, 
but  also  on  the  rocks  that  border  them.  These 
rocks,  rounded  by  the  ponderous  effort  of  the 
mass  that  presses  them,  often  assume  a  particular 
aspect,  which  renders  them  distinguishable  at  a 
distance,  wherever  a  glacier  has  worn  itself  a  bed. 
Some  of  these,  seen  far  away,  look  like  flocks  of 
sheep,  and  for  this  resemblance  De  Saussure  the 
naturalist  has  invented  the  term  roches  mouton- 
nees,  or  "  sheep-shaped  rocks." 

Another  order  of  phenomena  demands  our 
attention.  As  M.  Martins  has  well  said,  in  his 
"  Eesearches  on  the  Glacier  Period,"  "  The  Alps 
are  immense  ruins.  Every  thing  conspires  for 
their  destruction  ;  all  the  elements  seem  to  have 
combined  to  bring  down  their  proud  summits. 
The  masses  of  snow  that  weigh  upon  them  so 
heavily  in  winter,  the  rain  that  filters  in  be- 
tween their  beds  in  summer,  the  sudden  action 
of  torrents,  the  less  abrupt  but  still  more  power- 
ful operation  of  chemical  affinities,  wear  away, 
separate,  and  decompose  the  hardest  rocks.  Their 
debris  falls  from  the  upper  heights,  into  the  am- 
phitheatres occupied  by  the  glaciers,  in  the  form 
of  considerable  land-slides,  accompanied  by  a  ter- 
rific uproar  and  immense  clouds  of  dust.  Even 


94  METEORS   AND   METEOEIC   PHENOMENA. 

in  midsummer  I  have  seen  avalanches  of  stone 
precipitate  themselves  from  the  uppermost  sum- 
mits of  the  Schreckhorn,  and  form  upon  the  hith- 
erto spotless  snow  a  long  black  streak,  made  up 
of  enormous  blocks  and  a  countless  number  of 
smaller  fragments." 

These  blocks,  some  of  which  measure  from 
ten  to  twenty  yards  in  thickness,  either  way,  are 
borne  along  by  the  glacier,  and  consequently 
form  long  streaks,  which  skirt  across  its  borders, 
or  accumulate  in  transversal  lines  at  its  extremi- 
ties. These  streaks  of  debris,  left  by  the  ava- 
lanches and  land-slides,  have  received  the  name 
of  moraines. 

MOVEMENTS  OF  THE  GLACIERS. PRIMITIVE  GLACIERS. 

By  these  interesting  observations,  not  only 
has  the  movement  of  the  glaciers  been  circum- 
stantially proved,  but  we  have  been  enabled  to 
demonstrate  their  ancient  extent  by  the  furrows 
grooved  in  the  rock  by  the  primitive  glaciers,  and 
by  following  in  the  valleys  the  traces  of  their  lat- 
eral and  transversal  'moraines. 

Thus,  the  glaciers  of  Mont  Blanc  once  extended 
from  Chamouni  to  Geneva.  On  the  eastern  slope 
of  Jura  there  are  found  isolated  bowlders,  or  wan- 
dering blocks,  so  called,  of  granite,  which  can  have 


MOVEMENTS  OF  THE  GLACIERS.  95 

come  from  no  other  source  than  the  mountains  of 
Switzerland,  the  Jura  chain  being  composed  of 
calcareous  stone.  The  immense  glacier,  which 
transported  these  blocks  to  the  height  of  a  thou- 
sand yards  above  the  level  of  the  sea,  extended 
across  the  plain  that  is  comprised  between  the 
Alps  and  the  Jura.  It  was,  in  Martins's  opinion, 
the  principal  glacier  of  Switzerland,  the  others, 
which  are  also  indicated  by  the  plainest  traces, 
being  but  its  tributaries. 

To  Jean  Perraudin,  a  chamois-hunter,  the 
first  idea  of  this  cataclysm  is  due.  A  learned 
geologist,  M.  de  Charpentier,  to  whom  he  had 
communicated  the  result  of  his  observations, 
made  it  the  subject  of  persevering  research,  and 
obtained  the  most  incontestable  proof  of  the 
grand  phenomenon  which  had  been  pointed  out 
to  him.  The  study  of  the  glacier  period  is  thus 
connected  with  the  revolutions  of  which  our 
globe  has  been  the  theatre.  Numerous  scientific 
works,  among  which  we  must  mention  in  the  first 
rank  those  of  M.  Agassiz,  have  indicated  in  the 
two  hemispheres  the  same  traces  of  antediluvian 
glaciers,  extending  over  the  wide  plains  that  sur- 
round our  mountain-ranges. 

Professor  Tyndall,  in  his  fine  work  on  "  The 
Glaciers  of  the  Alps,"  attributes  the  present  con- 


96  METEORS   AND   METEORIC   PHENOMENA. 

formation  of  the  Alpine  chain,  in  a  great  measure, 
to  the  movements  of  those  prodigious  masses  of 
ice  which  have  traced  immense  furrows  in  the 
rock,  hollowed  out  the  valleys  to  great  depths  as 
they  passed,  and  by  this  very  action  prepared  their 
partial  destruction.  In  fine,  Mr.  Tyndall  explains 
that  the  currents  of  warm  air  that  rise  from  the 
valleys  toward  the  heights,  have  a  temperature 
the  more  elevated  and  a  force  the  greater  the 
deeper  the  valley  is.  Hence  it  results  that  the 
glacier  grows  smaller  as  it  sinks  lower,  and  that 
it  reaches  limits  at  last  which  it  cannot  pass. 
This  equilibrium  between  the  thaws  of  summer 
and  the  increase  and  advance  of  winter  appears  to 
be  established  at  the  present  day,  and,  with  some 
rare  exceptions,  we  know  the  mean  limit  beyond 
which  the  ice  never  goes. 

We  find  among  the  Pyrenees,  the  Vosges,  the 
mountains  of  Scotland,  and  the  principal  ranges 
on  the  globe,  the  same  traces  of  an  immense  de- 
velopment of  primitive  glaciers.  We  are  igno- 
rant, as  yet,  of  the  cause  of  this  phenomenon,  super- 
induced, as  it  was,  no  doubt,  by  meteorological 
conditions  very  different  from  those  now  ex- 
isting, but  which  persevering  observation  of  the 
disturbances  taking  place  under  our  eyes  will 
perhaps  enable  us  to  discover.  Thus,  Professor 


MOVEMENTS    OF   THE    GLACIEKS.  97 

Frankland,  of  the  Royal  Institution  of  London, 
lias  recently  shown  that  the  limit  of  the  eternal 
snows  is  higher  in  the  interior  of  continents  than 
in  the  vicinity  of  seas.  It  may  be  readily  under- 
stood, in  fact,  how  an  abundant  production  of 
watery  vapor  is  one  of  the  principal  causes  of  the 
formation  of  glaciers,  the  vapor  becoming  snow 
and  ice  in  the  high  regions  of  the  atmosphere. 
But  the  abundance  of  aqueous  meteors  is  also  in 
correspondence,  as  we  have  seen,  with  the  temper- 
ature, so  that  it  is  impossible  to  admit  the  exist- 
ence of  the  immense  glaciers  of  which  the  traces 
and  deeply-worn  channels  are  found  on  all  sides, 
at  the  very  period  when  the  mean  temperature  of 
the  globe  was  above  the  present  temperature. 
The  chains  of  mountains,  which  had  just  then  ap- 
peared, had  not  yet  been  encroached  upon  by  the 
slow  but  potent  action  of  the  different  agents  of 
destruction  that  excavate  and  reduce  them,  and 
those  primitive  chains  presented  a  vast  surface 
for  the  accumulation  of  snow  and  ice,  the  forma- 
tion of  which  was  favored  by  the  more  frequent 
vicinity  of  great  lakes  and  interior  seas,  such  as 
the  ancient  sea  of  Sahara,  indicated  by  Charles 
Lyell  in  his  "  Principles  of  Geology." 

Maury,  in  his  excellent  researches  on  the  geo- 
logical part  performed  by  the  winds,  has  put  in 


98  METEORS    AND   METEORIC    PHENOMENA. 

the  way  of  completion  some  important  discoveries 
regarding  the  relations  that  subsist  between  the 
quantity  of  moisture  set  in  circulation  by  the  at- 
mosphere and  the  configuration  of  the  seas  and 
continents.  The  action  of  the  great  aerial  cur- 
rents, as  well  as  that  of  the  great  oceanic  cur- 
rents, varies  with  the  circumstances  that  favor 
or  obstruct  it,  and  these  variations  are  in  close  re- 
lation to  the  distribution  of  heat  upon  the  globe. 
It  is  to  these  causes,  which  are  still  incessantly  at 
work,  that  Mr.  Lyell  attributes  also  "  the  principal 
revolutions  of  the  meteorological  condition  of  the 
atmosphere  at  different  geological  epochs." 

The  conflict  of  the  elements,  subjected,  accord 
ing  to  the  region,  to  the  influence  of  heat  and 
cold,  necessarily  produced  convulsions  correspond- 
ing in  extent  and  intensity  to  the  greater  or  less 
power  of  these  influences,  and  left  on  the  surface 
of  the  globe  the  deep  traces  that  science  discov- 
ers there  to-day.  "  The  phenomena,"  says  M. 
Martins,  "  have  remained  the  same ;  but,  instead 
of  those  gigantic  manifestations  characteristic  of 
the  geological  epochs  preceding  our  own,  they  re- 
strict themselves  to  the  limits  of  action  which 
have  been  imposed  upon  them  by  the  equilibrium 
of  the  period  of  repose  that  the  coming  of  man 
has  inaugurated  on  the  earth." 


POLAR   GLACIERS.  99 

POLAR    GLACIERS. 

The  limit  of  the  eternal  snows  descends  lower 
in  passing  from  the  equator  to  the  poles,  from  the 
glaciers  of  the  Cordilleras  that  cover  the  volca- 
noes of  Peru,  to  those  of  Spitzbergen,  which 
come  down  to  the  edge  of  the  sea,  and  fill  up  the 
bottom  of  the  bays.  These  last-mentioned  gla- 
ciers present  a  remarkable  peculiarity.  Upon  the 
western  coast  of  the  island,  bathed  by  one  of 
the  branches  of  the  great  lukewarm  current  of 
the  Atlantic — the  Gulf  Stream — the  sea  thaws 
during  the  summer,  and  melts  the  lower  part  of 
the  glaciers,  which,  continually  advancing,  at 
length  pass  beyond  the  shore.  The  parts  which 
are  no  longer  supported  below  are  then  seen  de- 
taching themselves  and  forming  the  field-ice  that 
is  met  with  in  such  quantities  in  the  Arctic  Ocean. 
Madame  Leonie  d'Aunet  has  described  this  phe- 
nomenon, as  follows,  in  her  interesting  "  Yoyage 
to  Spitzbergen" : 

"  During  my  sleep  the  thaw  had  commenced, 
and  the  physiognomy  of  the  day  had  changed  as 
though  by  a  miracle.  A  spectacle  of  the  utmost 
turbulence  and  agitation  had  succeeded  to  the 
motionless  solitude  of  the  evening  before.  A 
flotilla  of  islands  of  ice  surrounded  the  corvette, 


100         METEORS   AND   METEOKIG   PHENOMENA. 

and  covered  the  bay  as  far  as  the  eye  could  see. 
The  ices  of  the  pole,  which  no  dust  has  ever  soiled, 
as  pure  now  as  on  the  first  day  of  the  creation, 
are  tinged  with  the  most  vivid  colors.  One  would 
say  the  rocks  were  precious  stones.  One  sees  the 
sparkle  of  the  diamond,  and  the  dazzling  hues  ol 
the  sapphire  and  the  emerald,  blended  in  an  un 
known  and  marvellous  substance.  These  floating 
islets,  incessantly  undermined  by  the  sea,  change 
their  forms  at  every  instant.  By  an  abrupt 
movement  their  base  becomes  their  summit;  a 
needle  changes  to  a  mushroom;  a  column  imi- 
tates an  immense  table ;  a  tower  is  transformed 
to  a  staircase.  And  all  this  is  so  rapid  and  un- 
expected that  one  cannot  help  thinking  that  some 
supernatural  power  must  control  the  sudden 
transformations.  At  all  events,  from  the  first 
moment,  I  fancied  that  I  saw  before  me  the  ruins 
of  a  fairy  city  suddenly  destroyed  by  a  supe- 
rior power,  and  condemned  to  disappear  without 
leaving  a  single  vestige  where  it  had  stood.  I 
saw  fragments  of  architecture  in  every  style  and 
of  every  period  dashing  together  around  me — 
belfries,  columns,  minarets,  ogives,  pyramids, 
turrets,  cupolas,  crenellated  battlements,  volutes, 
arcades,  pediments,  colossal  masses  of  masonry, 
carvings  as  delicate  as  those  that  encircle  the 


VARIATIONS  OF  THE  SEASONS  AND  CLIMATES.  101 

slender  pillars  of  our  cathedrals — all  there  con- 
founded and  commingled  in  one  common  dis- 
aster. The  palette  could  not  reproduce,  and  mere 
description  cannot  convey,  an  idea  of  this  strange 
and  wondrous  combination. 

"  This  place,  where  every  thing  is  cold  and 
inert,  is  represented  as  being  wrapped  in  a  pro- 
found and  gloomy  silence,  is  it  not?  Well,  a 
totally  different  conception  of  it  must  be  formed. 
Nothing  could  reproduce  the  tremendous  tumult 
of  a  day  of  thaw  at  Spitzbergen. 

"  The  sea,  studded  with  sharp  pinnacles  of  ice, 
plashes  noisily ;  the  tall  masses  bristling  along  the 
coast  slide  down,  break  from  the  rest,  and  plunge 
into  the  gulf  with  a  terrific  crash ;  the  mountains 
crack  and  split  apart ;  the  waves  dash  furiously 
against  the  granite  capes ;  the  islands  of  ice  as 
they  break  up  make  a  succession  of  crackling 
sounds  like  discharges  of  musketry,  and  the  gust 
tosses  whirling  clouds  of  snow  on  high  with 
hoarse  roarings.  It  is  terrible !  It  is  magnificent ! 
One  seems  to  hear  the  choirs  of  the  abyss  of  the 
old  world  intoning  the  prelude  to  a  new  chaos." 

VARIATIONS   OF  THE   SEASONS   AND   OF   CLIMATES. 

"We  have  seen  how  the  melting  of  the  glaciers 
maintains  the  volume  of  the  rivers  during  the 


102         METEOKS   AND   METEOKIO   PHENOMENA. 

summer-time,  and  thus,  in  keeping  up  the  water- 
courses, contributes  to  refresh  and  fertilize  our 
fields.  The  floating  ices  of  the  pole,  which  then 
descend  toward  our  latitudes,  also  moderate  the 
heat  of  our  summers  by  the  influence  of  winds 
and  currents.  Sometimes,  even,  as  a  learned 
meteorologist,  M.  Renou,  has  remarked,  a  cold 
summer  like  that  of  1816  may  be  the  conse- 
quence of  a  great  breaking  up  of  the  polar  ices. 

The  regions  adjacent  to  the  two  poles  may  be 
considered  as  immense  glaciers,  resting  upon 
rocks  of  greater  or  less  elevation,  and  sometimes 
upon  lofty  mountains,  the  summits  of  which  pierce 
the  snow.  Two  volcanoes,  the  Erebus  and  the  Ter- 
ror, were  discovered  in  1841  by  Sir  James  Ross, 
during  his  expedition  to  the  Antarctic  regions. 
The  Erebus,  which  is  about  12,000  feet  in  height, 
and  covered  with  snow  to  the  crater,  threw  out 
dense  volumes  of  smoke  at  intervals. 

A  knowledge  of  the  causes  that,  in  these 
regions,  determines  the  periodical  increase  or 
diminution  of  the  ice,  would  be  of  great  interest 
for  the  general  meteorology  of  the  globe.  These 
variations  seem  to  be  connected  with  a  variation 
of  seasons  dependent  upon  the  periodicity  of  the 
solar  spots,  as  M.  Renou  indicates,  or  on  the 
movements  of  the  earth  in  its  orbit,  as  hinted  by 


VARIATIONS  OF  THE  SEASONS  AND  CLIMATES.    103 

Jean  Reynaud,  when  referring  to  the  secular  va- 
riation of  climates  in  his  "  Terre  et  Ciel."  But  a 
long  series  of  observations  on  the  glaciers  of  both 
hemispheres  would  be  necessary,  in  order  to  solve 
these  important  questions  with  any  certainty. 

Already  numerous  discoveries,  due  to  the  in- 
trepid zeal,  the  devotion,  and  the  scientific  skill  of 
the  great  explorers  who  penetrated  the  icy  soli- 
tudes of  the  pole,  and  the  burning  deserts  of  the 
equator,  or  climbed  the  perilous  summits  of  our 
highest  mountains,  have  opened  new  horizons  to 
investigation.  In  the  vast  totality  of  meteoric 
phenomena,  until  then  so  confused,  we  have, 
through  their  aid,  seen  a  few  simple  laws  stand 
forth  that  shall  hereafter  serve  to  guide  us  in 
studying  the  perturbations  of  the  atmosphere  and 
the  modifications  that  they  lead  to  on  the  surface 
of  the  globe. 


CHAPTEE  Y. 

THUNDER-STORMS. 


Luminous  Phenomena.— The  Fires  of  St.  Elmo.— Thunder-storms  among 
the  Mountains.— The  Forms  of  Lightning.— Globular  Thunder-bolts.— 
Thunder.— Singular  Effects  of  Lightning.— Lightning-rods.— Geogra- 
phy of  Thunder-storms.— Influence  of  the  Soil.— Volcanic  Storms.— 
Action  of  Thunder-storms  upon  the  Subterranean  Waters.— Utility 
of  Thunder-storms. 


LUMINOUS   PHENOMENA. FERES   OF   ST.    ELMO. 

THE  air  during  a  thunder-storm  is  some- 
times so  highly  charged  with  electricity,  that  it 
becomes  visible  in  the  midst  of  the  obscurity 
by  a  vivid  light  resting  on  all  surrounding  bodies, 
and  particularly  upon  the  water.  Mention  is 
made  of  luminous  rains,  during  which  the  ground 
seemed  to  be  on  fire.  More  than  once  travellers 
have  been  seized  with  alarm  on  seeing  their  wet 
clothes  all  aglow  on  stormy  nights.  A  curious 
narrative  addressed  by  M.  Allemand,  a  physician 
of  Meurier,  near  Neufchdtel,  to  Professor  Piotet, 
as  mentioned  in  the  Billiotheque  Universelle  of 
Geneva,  sets  forth  a  case  of  this  kind  : 


LTJMINOUS   PHENOMENA.  105 

"  On  the  third  of  May  last,  I  was  called  to 
Motiers  about  ten  o'clock  in  the  evening,  and  was 
surprised,  so  to  speak,  as  I  was  leaving  the  vil- 
lage, by  a  storm  that  was  quickly  followed  by  a 
very  heavy  rain.  Although  provided  with  a 
walking-stick  umbrella,  I  thought  I  had  better 
close  it,  as  the  thunder  grew  more  frequent  and 
severe,  and  I  even  held  the  upper  end,  which,  as 
you  may  know,  forms  a  metallic  point,  in  my 
hand ;  the  point  is  blunt  indeed,  yet  it  might  at- 
tract the  lightning.  Ere  long,  the  night,  which 
was  excessively  dark  already,  became  more  so 
with  torrents  of  rain,  and  it  was  only  by  the  help 
of  the  vivid  and  frequent  flashes  of  lightning, 
that  I  was  able  to  pursue  my  way.  Thus  moving 
along  through  the  most  violent  tempest  that  can 
be  imagined  in  our  part  of  the  country,  I  sudden- 
ly noticed  a  light  that  appeared  to  come  from 
above,  and,  at  once  raising  my  eyes,  I  remarked 
that  it  was  the  brim  of  my  hat  that  seemed  to  be 
illuminated.  Thinking  that  it  was  real  fire,  and 
without  taking  time  to  reflect,  I  suddenly  passed 
my  hand  along  the  luminous  edge,  expecting  to 
extinguish  it.  But,  to  my  great  surprise,  it  only 
shone  the  brighter,  and  this  gave  me  a  confused 
idea  that  I  had  been  mistaken  as  to  the  charac- 
ter of  the  light.  My  hand  was  full  of  water  that 


106         METEORS    AND   METEORIC   PHENOMENA. 

flowed  from  my  hat,  and,  in  making  a  motion  to 
shake  it  off,  I  saw  it  shine  like  a  piece  of  polished 
metal  reflecting  a  bright  light. 

"  Hereupon,  to  the  sensations  that  I  had  ex- 
perienced until  then,  succeeded  such  emotion  as 
caused  me  to  utter  half  aloud  an  exclamation  of 
fear.  I  was  then  about  one  hundred  paces  from 
the  Chaux  farm,  that  is  to  say,  about  ten  minutes' 
walk  from  Fleurier,  and  fifteen  or  twenty  from 
Motiers.  I  deliberated  for  a  moment  whether  I 
should  seek  shelter  in  the  farm-house,  or  continue 
on  my  way ;  but,  at  last,  some  scientific  reasoning 
in  my  own  mind,  and  profound  reliance  upon  the 
Supreme  Author  of  the  formidable  apparatus  by 
which  I  was  surrounded,  decided  me  to  push  on. 
Having  been  enabled  to  fill  my  hand  unharmed 
with  the  electric  water  that  gleamed  along  the 
brim  of  my  hat,  I  felt  emboldened  to  repeat  the 
experiment — although,  after  all,  I  did  so  the  sec- 
ond time  with  a  sort  of  fear  —  and  ascertain 
whether  this  phosphorescent  light  had  no  odor, 
and  whether  it  produced  neither  a  crackling 
sound  nor  sparkles  of  flame.  But  I  saw  only  the 
beautiful  light  I  had  remarked  in  the  first  in- 
stance, which  did  not  rise  from  my  hand  at  the 
moment  when  I  opened  it,  but  seemed  to  be  ap- 
plied to  its  surface  like  a  shining  varnish.  This 


LUMINOUS   PHENOMENA.  107 

light  lasted  only  for  an  instant.  Continuing  on 
my  way,  with  my  gaze  almost  constantly  riveted 
upon  the  brilliant  halo  that  bordered  my  hat,  I  saw 
another  vivid  light  on  the  surface  of  the  smooth 
handle  of  my  umbrella,  at  the  spot  where  the  me- 
tallic plate  is  usually  found  on  which  the  name  of 
the  owner  is  engraved.  My  first  movement  was 
to  pass  my  thumb  over  the  place,  in  order  to  ex- 
tinguish this  new  fire,  which  had  become  as  per- 
plexing to  me  as  the  other.  The  same  phenom- 
enon ensued ;  that  is  to  say,  the  part  rubbing  be- 
came quite  as  luminous  as  the  part  rubbed.  I 
then  felt  afraid  of  the  umbrella,  the  metallic 
mounting  of  which  was  continually  before  my 
mind,  and  I  threw  it  down.  The  thunder-claps 
increased,  although  the  electric  concussion  seemed 
to  be,  and  was,  indeed,  at  some  distance  from  me. 
Once  relieved  of  my  umbrella,  I  endeavored  to 
rub  the  rim  of  my  beaver  briskly  with  the 
sleeve  of  my  coat,  but  this  had  no  other  effect 
than  to  make  the  crown  of  light  more  vivid,  and 
I  arrived  with  it  at  Motiers.  I  attribute  its  ces- 
sation to  the  proximity  of  the  tall  poplars  that 
border  the  road  near  that  village." 

These  effects  are  explained  by  the  influence  of 
the  storm-clouds  in  the  upper  region  of  the  at- 
mosphere. The  latter  attract,  at  the  surface  of 


108         METEOKS  AND  METEOEIO   PHENOMENA. 

the  soil,  an  electricity  contrary  to  that  with 
which  they  are  charged.  Frequently  the  pencils 
of  rays  that  one  sees  at  the  extremity  of  the 
points  placed  on  an  electric  machine  in  operation, 
appear  in  enlarged  dimensions  upon  all  kinds  of 
salient  objects,  metallic  bars  and  uprights,  the 
spires  of  belfries,  and  the  masts  and  yard-arms  of 
ships.  Those  brilliant  little  flames,  which  sailors 
call  the  Jvres  of  St.  Elmo,  indicate  the  abundant 
emission  of  the  terrestrial  fluid,  neutralizing  the 
fluid  of  the  clouds.  "We  shall  cite,  in  addition  to 
the  above,  only  the  following  facts,  as  Arago 
gives  them : 

"  On  January  14,  1824,  just  after  the  close 
of  a  storm,  M.  Maxadorf,  happening  to  look  at  a 
wagon  loaded  with  straw,  in  the  middle  of  a 
field  near  Gothen,  over  which  hung  a  huge 
black  cloud,  observed  that  every  stalk  stood  out 
straight  and  seemed  on  fire.  Even  the  whip  of 
the  driver  threw  off  a  vivid  light.  The  phenom- 
enon disappeared  as  soon  as  the  wind  had  swept 
away  the  black  cloud,  but  it  had  lasted  ten  min- 
utes. 

"  On  the  8th  of  May,  1831,  after  sunset,  some 
officers  were  walking  bareheaded,  during  a  storm, 
on  the  terrace  of  the  Bab-Azoun  fort  in  Algiers, 
when  each  of  the  party  remarked  with  surprise, 


STORMS   AMONG    THE  MOUNTAINS.  109 

as  he  looked  at  his  neighbor,  that  there  were  little 
pencils  of  light  at  the  ends  of  his  hair.  When 
these  officers  raised  their  hands,  similar  luminous 
plumes  formed  at  the  ends  of  their  fingers." 

STORMS   AMONG  THE  MOUNTAINS. 

A  Swiss  engineer,  M.  Buchwalder,  was  en- 
gaged in  geodesic  operations  on  the  summit  of 
Mont  Sentis,  at  a  height  of  seven  thousand  five 
hundred  feet  above  the  level  of  the  sea,  when  he 
was  caught  in  a  violent  storm.  "  Heavy  clouds," 
he  says,  "  coming  from  the  west,  enveloped  the 
mountain.  Yery  soon  a  violent  wind  announced 
a  tempest ;  thunder  was  heard  in  the  distance,  and 
the  hail  fell  in  such  abundance  that,  in  a  few  min- 
utes, it  covered  Mont  Sentis  with  a  sheet  of  ice. 
We  took  refuge  in  our  tent,  and  I  carefully  closed 
all  the  openings  so  as  to  leave  no  hold  to  the 
wind.  For  a  few  moments,  the  storm  seemed  to 
abate,  but  it  was  only  an  interval  of  silence,  a  res- 
pite, during  which  a  terrible  crisis  was  in  prepara- 
tion. In  fine,  at  eight  o'clock  in  the  morning,  the 
thunder  was  heard  again,  but  much  nearer  and 
more  violent,  and  it  continued  thus,  for  hours  to- 
gether, without  cessation.  Tired  of  my  long  im- 
prisonment under  the  tent,  I  went  outside,  to  note 
the  condition  of  the  sky  and  measure  the  depth 


110         METEORS    AND   METEORIC   PHENOMENA, 

of  the  hail  that  had  fallen.  Scarcely  had  I  taken 
a  few  steps  in  the  open  air,  ere  the  thunder  burst 
over  my  head  with  such  fury  that  I  deemed  it 
prudent  to  regain  the  shelter  of  my  tent,  and  my 
aid  followed  my  example.  In  order  to  diminish 
the  danger  of  being  struck  by  the  lightning,  we 
lay  down  side  by  side  upon  some  planks.  At  this 
moment  a  cloud,  as  dense  and  black  as  night,  en- 
veloped Sentis.  The  rain  and  hail  fell  in  tor- 
rents ;  the  wind  blew  with  fury,  and  the  flashes 
of  lightning  succeeded  each  other  incessantly, 
crossing  and  recrossing  in  every  direction,  and 
surrounded  us  with  a  lurid  light  like  the  reflec- 
tion of  a  fire.  The  crashes  of  thunder,  rebounding 
from  the  precipitous  sides  of  the  mountain,  leaped 
from  echo  to  echo  with  such  vehemence  that  we 
could  scarcely  hear  ourselves  speak.  The  sound 
was  a  sharp,  rending  noise ;  a  quivering  crash,  as 
though  the  heavens  had  fallen  in,  and  a  dull  pro- 
longed roar,  all  in  one.  At  length,  the  fierceness 
of  the  storm  became  so  terrible  that  my  companion 
could  not  restrain  an  emotion  of  alarm,  and  asked 
me  if  we  were  not  in  imminent  danger  of  losing 
our  lives.  I  endeavored  to  reassure  him  by  men- 
tioning the  fact  that  Arago  and  Biot,  during  their 
observations  in  Spain,  were  surprised  by  a  simi- 
lar tempest.  The  lightning  had  struck  their  tent, 


STOKMS   AMONG  THE  MOUNTAINS.  Ill 

but  had  glanced  off  from  the  cloth  without  hurt- 
ing them. 

"  Hardly  had  I  told  him  this,  ere  I  heard  a  cry 
of  distress :  c  O  my  God ! ' — and  at  the  same  in- 
stant I  saw  a  ball  of  fire  flash  from  the  feet  to  the 
head  of  my  companion,  and  felt  a  violent  shock  in 
my  left  leg.  Our  tent,  also,  was  torn  asunder  in  the 
middle  with  a  terrific  detonation.  I  turned  toward 
my  companion ;  the  unfortunate  man  had  been 
struck  by  the  thunder-bolt !  In  the  light  yielded 
by  the  tearing  open  of  the  tent,  I  saw  the  left  side 
of  his  face  dotted  with  red  and  brown  spots  caused 
by  the  electric  fluid.  His  hair,  his  eyelashes,  and 
his  eyebrows,  were  singed  and  burnt ;  his  lips  and 
nostrils  were  a  livid  blue ;  his  breast  heaved  for 
a  moment,  and  then  the  sound  of  his  breathing 
ceased.  I  was  suffering  horribly  myself;  but, 
forgetting  my  own  mishap  in  my  anxiety  to  aid 
my  companion,  who,  I  saw,  was  dying,  I  called 
him  aloud,  I  shook  him,  but  he  made  no  response. 
His  right  eye,  which  was  wide  open,  brilliant  and 
full  of  intelligent  meaning,  seemed  turned  upon 
me  to  implore  my  assistance,  but  the  left  eye  re- 
mained closed,  and,  on  parting  the  lids,  I  saw 
that  it  was  dull  and  leaden.  I  still  thought  that 
there  was  a  remnant  of  life  in  him,  but  only  for  a 
moment ;  three  times  I  tried  to  close  that  right 


112         METEOES  AND   METEORIC   PHENOMENA. 

eye,  which  was  still  gazing  fixedly  at  me,  and 
three  times  it  opened  again,  with  all  the  look  of 
life.  I  then  placed  my  hand  over  his  heart ;  it 
no  longer  beat.  At  last,  my  grief  put  an  end  to 
this  distressing  examination.  My  own  left  leg 
was  paralyzed,  and  I  felt  an  acutely  painful 
shivering  in  it,  accompanied  by  an  extraordinary 
agitation  or  boilmg  of  the  blood.  A  convulsive 
tremor  ran  through  my  whole  body;  a  general 
stifling  sensation  half  choked  me,  and  my  heart 
beat  in  the  most  tumultuously  irregular  manner. 
Was  I  to  perish  like  my  hapless  companion  1 
Thank  God,  however,  I  managed  to  reach  the 
nearest  village,  after  extreme  exertion.  Subse- 
quently I  discovered  that  my  instruments  had 
been  struck  by  the  lightning,  for  every  metallic 
article  that  the  tent  contained  when  the  thunder- 
bolt fell,  bore  traces  of  the  passage  of  the  fluid. 
The  points,  edges,  and  most  delicate  parts,  were 
softened  and  melted." 

THE  FORMS   OF    LIGHTNING. GLOBULAR   LIGHTNING. 

Sometimes  the  clouds,  during  a  storm,  seem 
to  give  out  a  continual  emission  of  electricity,  for 
they  remain  luminous  a  long  time,  as  Kozier,  the 
physiologist,  observed,  during  a  storm  of  great 
intensity  that  he  witnessed  in  the  environs  of 


THE   FORMS   OF   LIGHTNING.  113 

Beziers.  "  Little  by  little,"  he  says, "  a  luminous 
point  that  made  its  appearance  in  the  midst  of 
dense  clouds,  assumed  breadth  and  volume.  It 
then,  by  imperceptible  degrees,  formed  a  zone,  or 
phosphorescent  band,  which  revealed  itself  to  my 
eyes  as  about  three  feet  in  height ;  it  at  last  sub- 
tended an  angle  of  sixty  degrees.  Above  this  first 
zone,  another  formed  of  about  the  same  height, 
but  of  not  more  than  thirty  degrees'  measurement. 
An  open  space  of  about  the  same  extent  separated 
them.  In  both  these  belts  were  noticed  irregular- 
ities similar  to  those  seen  on  the  edges  of  the 
heavy  clouds  that  are  the  forerunners  of  a  storm. 
These  edges  were  not  equally  luminous,  although 
the  centre  of  the  belts  presented  a  uniform  bright- 
ness. While  they  were  advancing  toward  the 
east,  the  lightning  darted  three  different  times 
from  the  end  of  the  lower  belt,  but  without 
any  appreciable  detonation."  This  phenomenon 
lasted  for  a  quarter  of  an  hour,  and  was  dispelled 
by  a  violent  gust  from  the  southward,  that  carried 
the  storm  to  a  distance. 

These  intermittent  discharges  of  electricity 
have  very  varied  forms,  and  traverse  the  atmos- 
phere with  astonishing  velocity.  Wheatstone  has 
demonstrated  that  the  most  brilliant  and  ex- 
tended lightnings — sometimes  from  fifteen  to 


114         METEOES   AND   METEORIC   PHENOMENA. 

eighteen  miles  in  length — do  not  last  the  thou- 
sandth part  of  a  second.  Some  consist  of  very 
delicate  shafts  of  light,  with  very  sharply-defined 
borders,  describing  zigzag  lines  in  space,  and 
sometimes  dividing  into  several  branches.  Most 
usually  they  are  white,  and  sometimes,  but  rarely, 
purplish,  violet-hued,  or  bluish. 

Others  extend,  on  the  contrary,  over  a  wide 
surface,  and  have  neither  the  whiteness  nor  the 
brilliant  illumination  of  those  before  mentioned. 
Their  hue  is  often  a  very  vivid  red.  "These 
lightnings,"  says  Arago,  "  appear,  sometimes,  to 
illuminate  only  the  outlines  of  the  clouds  from 
which  they  emanate.  Sometimes,  too,  their  viv- 
id light  embraces  the  entire  superficial  extent 
of  those  same  clouds,  and,  moreover,  seems  to 
issue  from  the  interior  of  them.  One  might  say 
with  truth  that  the  clouds  open.  Such  is  the 
popular  expression,  and  I  should  search  in  vain 
for  others  to  depict  the  same  phenomenon  more 
accurately." 

The  first  kind  of  lightning  is  much  more  rare 
than  the  second.  In  ordinary  storms,  hundreds  of 
the  latter  appear  for  every  one  instance  of  linear, 
or,  more  especially,  of  forked  lighting.  ~We  will 
here  quote  the  description  of  a  remarkable  storm 
observed  by  M.  Liais  during  his  sojourn  in  Brazil. 


THE   FORMS    OF   LIGHTNING.  115 

Although  it  was  the  30th  of  January,  the 
thermometer  marked  thirty-three  degrees.  "  Dur- 
ing the  night,  the  wind  came  up  very  feebly  from 
the  southwest ;  in  the  morning  the  air  was  pure, 
and  a  burning  sun  fell  upon  the  soil,  still  damp 
with  the  rain  of  the  preceding  days.  In  the  after- 
noon there  were  seen  some  cirri.  Toward  even- 
ing other  clouds,  cumulus  and  cumulo-stratus 
formed,  and,  at  sunset,  the  sky  was  almost  covered. 

"  At  seven  o'clock,  flashes  of  lightning  were 
seen  in  the  east,  and,  at  ten  minutes  past  seven, 
the  storm  had  acquired  all  its  intensity.  At  that 
time,  zigzag  lightnings  were  darting  forth  contin- 
ually, at  least  one-third  of  them  forked.  These 
flashes  were  white,  and  very  vivid.  Sometimes, 
they  seemed  to  tend  slightly  toward  a  bluish 
tinge,  and,  at  others,  were  of  an  orange  hue. 
They  did  not  form  interrupted  zigzags,  as  they  do 
in  many  storms,  but  rather  broken  lines,  and, 
moreover,  each  of  these  lines  was  sinuous.  These 
lightnings  did  not  end  in  points,  but  generally 
presented  a  slightly-rounded  form  at  the  ex- 
tremity where  they  terminated.  Although  these 
flashes  had  great  velocity,  it  seemed  to  me  that 
their  development,  and  the  manner  of  their  prop- 
agation, could  be  followed  with  greater  facility 
than  in  ordinary  storms.  Two  flashes  were  very 


116         METEORS   AND   METEORIC   PHENOMENA. 

rarely  seen  at  the  same  time,  and  their  emission 
had  a  certain  regularity. 

"  The  most  of  these  flashes  were  unaccom- 
panied by  any  noise.  From  time  to  time  we 
could  hear  a  slight  rumbling  in  the  distance,  but, 
owing  to  its  frequency,  without  being  able  to  dis- 
tinguish to  what  flash  it  belonged.  Many  of 
them  seemed  to  issue  from  a  sort  of  very  small 
cumulus,  situated  but  a  little  distance  above  the 
horizon,  and  to  propagate  themselves  with  an 
apparent  ascensional  movement.  Others  seemed 
to  issue  from  the  upper  bed  of  clouds,  with  an 
apparent  inverse  movement.  The  storm  was  not 
accompanied  by  rain.  Only  at  the  beginning  a 
few  large  drops  had  fallen.  The  upper  cloud, 
upon  which  the  lightnings  shot  out  in  relief,  did 
not  cover  the  entire  face  of  the  sky,  and  a  few 
stars  could  be  seen. 

"  I  pass  on  now  to  the  most  singular  part  of 
the  phenomenon.  Besides  the  two-forked  light- 
nings and  those  with  three  or  four  offshoots,  which 
were  also  very  frequent,  not  a  moment  went  by 
without  our  seeing  also  what  might  be  termed 
arborescent  or  tree-shaped  lightning.  These  were 
flashes  that  divided  themselves  into  several  prin- 
cipal branches,  which  in  their  turn  split  oft'  into 
a  multitude  of  smaller  boughs,  that  again  pre- 


THE   FOEMS   OF  LIGHTNING.  117 

sented  the  same  sinuosities,  and  the  same  round- 
ed endings  noticed  in  the  other  flashes.  There  was 
no  other  means  of  counting  these  branches  than 
by  reproducing  immediately  on  paper  the  impres- 
sion made  on  the  retina  of  the  eye.  One  of  these 
flashes,  that  I  had  remarked  particularly,  and  that 
had  appeared  to  propagate  itself  as  it  descended, 
divided,  at  first  into  two  branches,  which  subdi- 
vided in  their  turn,  in  such  manner  as  to  form 
fifteen  branches  in  all.  Another  was  of  radiating 
form,  and  one  arborescent,  that  is  to  say,  its  prop- 
agation was  in  every  direction,  but  starting  from 
a  common  centre. 

"  The  tempest  seemed  to  continue  motionless. 
At  the  end  of  about  ten  minutes,  the  frequency 
of  the  flashes  diminished  ;  at  a  quarter  past  eight, 
they  ceased,  and  the  clouds  soon  dispersed.  The 
zodiacal  light  was  seen  in  the  west  and  the  east, 
below  the  milky  way,  spanning  the  entire  sky. 
It  may  be  well  to  mention  that  on  the  preceding 
evening  the  phosphorescence  of  the  sea  was  ex- 
traordinary, and  such  as  I  had  never  seen  it  be- 
fore. On  the  evening  of  the  storm,  on  the  con- 
trary, it  had  resumed  its  usual  appearance  under 
the  tropics." 

In  another  storm,  M.  Liais  again  noticed  the 
extremely  curving  shape  of  the  ends  of  the  arbo- 


118         METEORS  AND   METEORIC    PHENOMENA. 

rescent  flashes,  and  a  still  more  marked  tendency 
to  terminate  in  balls  of  fire.  Three  times  these 
balls  broke  off,  leaving  a  train  of  light  behind 
them,  like  a  lolide,  and  traversing  an  arc  on  the 
sky  of  thirteen  degrees  in  half  a  second.  We  have 
seen  the  origin  of  a  third  kind  of  lightning,  which 
the  physiologists  call  globular  lightning,  without 
being  able,  up  to  the  present  time,  either  to  ex- 
plain it  or  to  imitate  it,  as  they  do  with  ordinary 
lightning.  It  is  entirely  analogous,  excepting  in 
dimensions,  to  the  sparks  of  an  electric  battery. 
These  globes  of  fire,  which  are  sometimes  as  large 
as  a  bomb,  descend  to  the  ground  with  a  motion 
slow  enough  to  enable  the  observer  to  note  their 
shape.  Their  color  varies  from  dead  white  to 
vivid  red.  In  advancing  along  the  soil,  they 
seem  to  keep  aloof  from  the  surface  of  objects 
and  emit  no  heat.  They  are  sometimes  seen  to 
stop  for  an  instant,  then  to  advance  again,  and 
then  rebound,  like  an  elastic  ball,  or  divide  into 
several  smaller  globes.  Sometimes,  at  the  end  of 
their  course,  a  plume  seems  to  issue  from  them, 
and  then  they  explode  with  a  noise  like  that  of  a 
cannon,  hurling  zigzag  lightnings  on  all  sides  of 
them,  that  produce  the  most  fearful  ravages. 


THUNDER.  119 


THUNDER. SINGULAR  EFFECTS  OF  LIGHTNING-STROKE. 

The  sound  caused  by  a  single  flash  of  light- 
ning sometimes  lasts  without  interruption  as  much 
as  forty-five  seconds.  Although  it  is  true  that  all 
the  beds  of  air  lying  along  the  course  of  the  im- 
mense electric  spark  are  shaken,  so  to  speak,  at 
the  same  time,  the  sound  developed  at  each  point 
reaches  the  observer  only  by  successive  concus- 
sions, and  the  difference  in  distance  produces  the 
variations  noticed  in  the  violence  of  the  thunder, 
its  rolling  reverberations,  and  its  sudden  crashes, 
repeated  again  and  again  by  the  echoes.  The 
discharges  that  take  place  between  a  cloud  and 
any  terrestrial  object  are  the  most  severe. 

We  cannot  account  for  some  of  the  phenom- 
ena of  transporting  power  revealed  by  lightning, 
unless  we  call  in  some  other  force  than  electricity. 
It  was  beyond  all  doubt  the  power  of  steam  alone, 
eliminated  on  its  passage,  which  could,  for  instance, 
lift  a  wall  weighing  twenty-six  tons,  and  carry  it 
in  one  mass  a  distance  of  many  yards.  Repeat- 
edly, the  roofs  of  huge  edifices  have  been  swept 
off  as  though  by  the  explosion  of  a  mine. 

In  passing  through  bodies,  the  lightning  very 
rapidly  raises  their  temperature.  Metallic  con- 
ductors nearly  a  third  of  an  inch  thick  have  been 


120         METEORS    AND    METEORIC    PHENOMENA. 

melted  by  it,  and,  when  of  less  dimensions,  have 
been  completely  volatilized.  Bell-wires  are  found 
incrusted  in  tiny  drops  in  the  floor,  or  shot  in  fine 
dust  over  the  walls. 

Travellers  often  see  the  surface-beds  of  rock 
on  the  tops  of  mountains  vitrified  by  the  lightning. 
When  it  penetrates  beds  of  sand  it  forms  tubes 
of  melted  and  adhering  quartz,  sometimes  thirty 
and  forty  feet  in  length,  which  have  received  the 
name  of  fulgurites.  The  following  fact  is  cited 
by  M.  Jamin :  "  On  the  17th  of  July,  1823,  the 
lightning  struck  a  birch-tree,  near  the  village  of 
Rauschen,  on  the  borders  of  the  Baltic.  The  in- 
habitants, who  hurried  to  the  spot,  saw  two  deep, 
narrow  holes  close  to  the  tree,  and  one  of  them 
seemed  warm  to  the  touch,  notwithstanding  the 
rain.  Professor  Hagen,  of  Koenigsberg,  caused 
the  ground  around  the  holes  to  be  dug  away  with 
great  care.  The  warm  one  presented  nothing 
peculiar ;  the  other  also,  for  the  depth  of  a  foot  or 
so,  offered  nothing  remarkable,  but  a  little  lower 
down  commenced  a  vitrified  tube.  The  fragility 
of  the  tube,  however,  did  not  admit  of  its  being 
taken  out  in  pieces  over  an  inch  or  two  in  length. 
The  inside  glassy  lining  was  very  shiny,  of  a 
pearl-gray  color,  and  studded  with  black  points 
along  its  entire  extent." 


LIGHTNING-EODS.  121 

Masses  of  iron  and  steel  traversed  by  lightning 
become  magnetic,  and  numerous  observations  show 
that,  on  board  of  vessels  that  have  been  struck,  the 
compasses  have  been  made  to  deviate  from  their 
normal  direction.  Trees,  which  are  excellent  con- 
ductors, because  of  their  moisture,  are  often  struck. 
In  such  cases,  where  the  burning  of  the  tree  has 
not  ensued,  the  trunk  is  seen  to  be  dried  up  and 
divided  into  long  strips.  Inside  of  houses,  all 
combustible  bodies  take  fire  on  the  passage  of 
lightning  through  them. 

LIGHTNING-EODS. 

The  identity  of  electricity  and  lightning  was 
proved  by  Franklin.  "  In  order  to  verify  a  con- 
jecture he  had  formed  on  the  subject,"  says 
Mignet,  one  of  his  biographers,  "  he  undertook 
to  draw  electric  fluid  from  the  clouds.  The  first 
means  that  occurred  to  him  was  to  erect  point- 
ed iron  rods  that  might  attract  it  This  device 
not  seeming  practical  to  him,  upon  mature  reflec- 
tion, because  he  could  not  find  any  place  suffi- 
ciently high,  he  conceived  another.  He  constructed 
a  kite  of  two  pieces  of  stick,  covered  with  a  silk 
handkerchief.  The  longer  stick  he  terminated 
with  an  iron  point  at  its  upper  extremity.  He 
then  tied  to  the  kite  a  hempen  cord  ending  with 


122         METEORS    AND   METEORIC   PHENOMENA. 

a  silk  one.  Where  the  hempen  cord,  which  was 
a  conductor,  and  the  silken  one,  which  was  not, 
joined,  he  fastened  a  key,  so  that  the  electricity 
might  accumulate  there  and  throw  off  sparks  an- 
nouncing its  presence.  With  his  apparatus  thus 
prepared,  Franklin  went  out  to  the  fields  one  day 
during  a  storm.  His  kite,  carefully  secured  by  its 
string,  which  was  in  its  turn  made  fast  to  the  silk 
cord,  was  given  to  the  air,  while  Franklin  himself 
stood  aloof  and  watched  it  with  anxiety.  For 
some  time  he  saw  nothing,  and  was  afraid  that  he 
had  been  mistaken  ;  but,  all  at  once,  the  string  at 
both  ends  stiffened  and  the  key  became  charged. 
It  was  the  electricity  descending.  Franklin  hast- 
ened to  the  spot  where  he  had  secured  the  string 
at  the  lower  end,  presented  his  finger  to  the  key, 
and  received  a  smart  shock  that  might  have  killed 
him,  but,  as  it  was,  only  filled  him  with  delight." 
By  the  invention  of  the  lightning-rod,  Frank- 
lin proposed  to  neutralize  the  effects  of  thunder- 
clouds by  furnishing  them  with  an  electricity  the 
opposite  of  their  own.  He  protected  buildings 
with  long  metallic  rods,  terminating  in  sharp 
points  at  the  top,  and  communicating  with  the 
ground.  Along  these  the  terrestrial  electricity 
escapes  toward  the  overhanging  cloud,  and  neu- 
tralizes it  more  or  less  rapidly.  Sometimes,  dur- 


LIGHTNING-RODS.  123 

ing  the  night,  tall  plumes  of  electric  light  are  seen 
shining  on  these  points.  It  may  happen  that  the 
cloud  is  not  sufficiently  discharged,  and  the  light- 
ning may  strike  between  it  and  the  edifice.  How- 
ever, in  that  case,  it  falls  upon  the  stem  of  the  rod, 
which  is  connected  with  the  ground  by  an  isolated 
conductor. 

The  efficacy  of  lightning-rods  is  fully  demon- 
strated by  statistics.  Mr.  Snow  Harris  reports, 
for  instance,  that  in  Devonshire  six  churches  with 
tall  steeples  having  been  struck,  one  of  them 
only,  that  was  protected  by  a  lightning-rod,  suf- 
fered no  damage.  The  Church  of  St.  Mark  at 
Venice,  the  Yalentino  palace  at  Turin,  the 
tower  of  Sienna,  all  in  cities  where  the  lightning 
causes  frequent  damage,  have  likewise  been  pre- 
served by  lightning-rods. 

We  well  remember  the  terrible  thunder-storm 
that  burst  over  the  city  of  Strasburg  on  the  14th 
of  August,  1833,  about  four  o'clock  in  the  after- 
noon. The  tower  of  the  cathedral  was  struck 
three  times  in  the  space  of  a  quarter  of  an  hour. 
At  the  last  stroke,  the  whole  pile  appeared  to  be 
in  flames  for  some  seconds.  In  many  places,  the 
lead,  the  copper,  the  iron,  and  even  the  mortar 
were  found  to  be  melted,  or  vitrified.  Fragments 
of  metal  had  soldered  themselves  to  the  bells,  and 


124:         METEOES   AND   METEORIC   PHENOMENA. 

it  was  found  difficult  to  detach  them.  Yery  large 
masses  of  stone  fell  in  the  neighboring  streets. 
In  the  next  year,  one  of  the  turrets  was  cut  in  two 
by  the  lightning,  and  it  was  at  last  decided  to 
put  up  lightning-rods  on  the  spire  and  other  parts 
of  the  edifice.  Since  that  time,  it  has  been  re- 
marked, as  a  matter  of  fact,  that  it  has  been 
struck  by  harmless  discharges  only,  which  fell  on 
the  rods  and  followed  the  conductors  into  the 
ground,  without  the  least  deviation.  Moreover, 
thunder-storms  appear  to  have  become  less  fre- 
quent and  less  intense  over  Strasburg. 

Let  us,  also,  mention  the  following  instance, 
where,  as  Arago  phrases  it,  "  Nature  was  caught 
in  the  act."  "  On  the  21st  of  May,  1831,  during 
a  very  violent  thunder-storm,  the  ship  Caledonia 
was  under  sail  in  Plymouth  Bay.  From  the 
town,  the  lightning  could  be  seen  darting  toward 
the  water,  at  but  a  short  distance  from  the  vessel. 
It  fell  also  on  the  shore  and  there  caused  several 
accidents.  Surrounded,  as  it  were,  by  these  fall- 
ing thunder-bolts,  the  Caledonia,  protected  by  her 
lightning-rods,  yet  escaped  all  harm  and  sailed 
along  as  safely  as  though  the  sky  had  been  clear." 

Extreme  care,  as  recommended  by  all  our 
learned  associations,  but  too  often  neglected,  is 
required  in  the  construction  and  keeping  of  the 


LIGHTNING-RODS.  125 

lightning-rod.  It  is  of  special  importance  that 
the  point  should  be  of  metal  that  will  not  oxidize, 
and  that  the  conductor  should  be  united  with  iron 
ligatures  to  all  the  large  metallic  pieces  of  the 
structure,  and  be  in  perfect  communication  with 
the  ground.  In  damp  soil,  the  electric  flow  and 
dispersion  are  very  easy,  but  the  iron  rusts  and  is 
quickly  worn  out.  In  a  dry  soil,  there  would  be 
insulation,  and  great  mishaps  might  be  appre- 
hended. The  conductor  in  such  a  case  must  be 
made  to  run  into  a  pit  full  of  slacked  cinders ;  coal, 
when  it  has  been  red  heated,  being  an  excellent 
conductor,  while  it  has  the  additional  good  prop- 
erty of  not  attacking  iron.  When  there  is  a  nat- 
ural sheet  of  water  in  the  vicinity,  the  conductor 
might  be  led  into  it,  and  provided  with  numer- 
ous branching  pieces  where  it  does  so.  A  reser- 
voir or  cistern  cannot  be  considered  in  the  same 
light  as  a  well  or  pit,  properly  speaking,  since  the 
stone  blocks  and  the  cement  that  line  its  bot- 
tom and  sides  yield  but  difficult  passage  to  elec- 
tricity ;  there  is  no  free  dispersion,  and  a  violent 
concussion  might  ensue. 

The  difference  in  the  conducting  power  of 
different  soils,  and  of  the  bodies  placed  there, 
should,  as  well  as  their  form,  direct  the  choice  of 
localities  in  which  one  is  the  least  exposed  to  be 


126         METEORS   AND   METEOEIC   PHENOMENA. 

struck  by  lightning.  According  to  the  considera- 
tions presented  in  the  foregoing  pages,  care  must 
be  taken  not  to  get  under  trees,  or  to  go  too 
near  to  large  metallic  masses,  or  very  high,  build- 
ings. 

Men  and  animals  have  been  killed  beneath 
a  thunder-cloud,  without  being  struck  directly 
by  lightning.  This  phenomenon,  called  the  re- 
turn-stroke by  physiologists,  is  explained  by  the 
influence  of  a  very  extensive  electrified  cloud, 
discharged  at  one  of  its  extremities  by  lightning. 
If,  at  that  moment,  then,  bodies,  beneath  the 
other  extremity  being  powerfully  influenced,  re- 
turn suddenly  to  their  natural  condition,  they 
experience  a  very  violent  shock. 

THE   GEOGRAPHY   OF   THUNDER-STORMS. 

Humboldt  found  vitrified  surfaces,  caused  by 
lightning,  on  the  summit  of  the  mountain  of 
Toluca,  at  the  height  of  13,860  feet  above  the 
level  of  the  sea.  This  fact  does  not  prove  that 
thunder-clouds  can  attain  that  elevation,  for  there 
are  cases  on  record  where  lightning  has  struck  the 
tops  of  mountains,  starting  from  their  base.  On 
the  other  hand,  again,  the  inhabitants  of  Chamouni 
affirm  that  thunder-storms  have  passed  over  the 
summit  of  Mont  Blanc,  which  is  14,430  feet  high. 


THE    GEOGRAPHY    OF   THUNDER-STORMS.         127 

Arago  gives  228,  and  even  91  feet  as  the  lower- 
most limit,  which,  according  to  exact  measure- 
ment, can  be  assigned  to  thunder-storms. 

The  principal  elements  in  the  geographical 
distribution  of  thunder-storms  are  in  relation  with 
the  distribution  of  rain.  Nearly  all  the  rain  of 
the  tropical  regions  falls  from  thunder-clouds,  and 
under  the  equatorial  belt  one  hears  the  rumbling 
of  thunder  almost  continuously.  At  Calcutta 
sixty  thunder-storms  per  annum  are  counted,  and 
among  them  forty-five  occur  during  the  southwest 
monsoon,  that  is  to  say,  from  April  to  September. 
There  are  none  from  November  to  January,  or 
during  the  northeast  monsoon.  We  have  already 
referred  to  the  exceptional  case  of  Peru,  where 
the  inhabitants  have  never  heard  thunder. 

In  the  zone  of  tropical  calms,  thunder-storms 
are  frequent ;  less  so,  however,  than  under  the 
equator.  The  example  of  Europe  may  give  an 
idea  of  the  state  of  things  in  the  middle  latitudes. 
In  southern  Spain  there  are  the  same  number  of 
thunder-storms,  say,  from  five  to  ten,  as  in  Eng- 
land and  Scandinavia.  Italy,  the  Adriatic  Sea,  and 
Greece,  present  the  maximum  of  the  European 
ratio  of  thunder-storms.  Janina  and  Rome  have 
forty-five  and  forty  respectively  per  annum. 
Among  the  Alps  about  thirty  are  counted.  In 


128         METEORS   AND   METEORIC   PHENOMENA. 

France  and  Germany  there  are  from  fifteen  to 
twenty.  In  the  latter  country,  however,  certain 
localities,  such  as  Munster,  Braunsberg,  etc.,  which 
are  exposed  to  frequent  thunder-storms,  are  re- 
markable exceptions  to  this  rule.  It  is  in  the 
Adriatic,  and.  upon  the  western  coasts  of  Europe, 
that  the  winter  thunder-storms  are  most  frequent. 
As  we  advance  toward  the  east,  they  become  less 
numerous,  and,  beyond  the  frontiers  of  Germany, 
only  summer  thunder-storms  are  noticed. 

In  the  high  latitudes,  thunder-storms  are  ex- 
tremely rare.  Sometimes  as  long  a  period  as  six 
years  will  pass  without  thunder  being  heard  in 
Greenland.  Farther  on  we  shall  state  how  the 
thunder-storm  is  replaced  in  those  regions  by  the 
splendid  phenomena  of  the  aurora  borealis. 

In  the  tropics,  thunder-storms  are  always 
caused  by  ascending  atmospheric  currents,  and 
the  same  is  the  case  with  the  summer  thunder- 
storms of  the  temperate  zones.  They  take  place 
every  afternoon,  when  the  arrangement  of  the 
country  is  favorable  to  them.  Above  some  of  the 
lakes  of  Switzerland  there  thus  daily  appears  a 
small  cloud  that  moves  over  and  fixes  itself  on 
the  slope  of  a  neighboring  mountain,  and  then 
bursts  with  a  terrific  concussion.  We  have  no- 
ticed this  periodical  formation  of  thunder-storms, 


THE   GEOGRAPHY   OF   THUNDER-STORMS.        129 

toward  the  close  of  summer,  in  the  bays  of  Naples 
and  Tunis. 

The  thunder-storms  of  the  temperate  zone 
usually  accompany  the  heavy  rains  that  result 
from  the  meeting  of  the  equatorial  and  the  polar 
currents.  There  then  ensues  a  struggle  between 
the  two  winds  that  often  lasts  for  several  days, 
and  the  result  of  which  determines  the  state  of 
the  weather.  With  the  south  winds,  the  air  be- 
comes heavy,  warm,  and  damp,  and  dense  clouds 
ascend  along  the  horizon.  But  suddenly  the 
northern  gust  sweeps  down,  accompanied  with 
electric  explosions.  The  fluctuations  of  these 
currents  occasion  several  consecutive  thunder- 
storms, which  exhibit  no  periodicity,  and  are  of 
very  variable  duration.  Should  the  polar  wind 
prevail,  all  the  vapors  dissolve  in  rain,  or  are 
borne  off  to  a  distance,  and  the  sky  clears  up 
again.  Upon  other  occasions,  it  is  the  north 
wind  .that  rules  at  the  outset,  with  clear,  dry,  and 
cold  weather,  which  the  arrival  of  the  south  wind 
changes.  This  current  is  indicated  in  the  high 
latitudes  by  the  cirrus,  which  rapidly  grows  more 
dense,  changes  to  cumulus,  and  covers  the  sky  with 
a  thick  veil  of  clouds,  whence  the  lightning  soon 
begins  to  play.  When  the  north  wind  yields,  the 
thunder-storm  winds  up  with  mild  weather  and 


130         METEORS    AND  -METEORIC   PHENOMENA. 

those  long  rains  that  are  so  powerful  a  source  of 
fertility  in  the  temperate  zones. 

INFLUENCE    OF   THE    SOIL. VOLCANIC    THUNDER- 
STORMS. 

According  to  some  meteorologists,  the  nature 
of  the  ground  may  contribute  to  the  frequency  of 
thunder-storms.  "In  the  department  of  May- 
enne  "  (in  France),  says  M.  Blavier,  a  mining- 
engineer,  "  there  exist  masses  of  diorite  (a  species 
of  rock  in  which  loadstone  is  sometimes  found), 
which  contain  a  notable  proportion  of  iron,  and 
affect  the  needle  of  the  compass.  We  were  as- 
sured that  in  certain  parishes,  such  as  Niort,  for 
instance,  the  most  threatening  thunder-clouds 
would  be  seen  to  disperse  as  they  drew  near,  or 
to  turn  aside  in  certain  directions.  We  think  that 
the  conducting  force  of  several  considerable  masses 
of  diorite  will  explain  this  phenomenon."  The 
savant  Yicat  reports  the  following  observation, 
made  at  Grondone,  a  village  situated  among  the 
Apennines,  near  a  very  rich  iron-mine,  that  rises 
in  the  form  of  an  isolated  peak.  "  Nearly  every 
day,  in  the  months  of  July  and  August,  an  electric 
cloud  is  seen  forming  above  this  region.  The 
cloud,  growing  larger  by  insensible  degrees,  re- 
mains for  some  hours  suspended  over  the  mine, 


INFLUENCE   OF   THE   SOIL.  131 

and  then,  in  bursting,  discharges  itself  toward  the 
peak,  which  is  almost  entirely  metallic.  The 
miners,"  adds  Yicat,  "  instructed  by  experience, 
judge  when  it  is  time  to  quit  the  spot.  They,  at 
the  right  moment,  retire  some  distance,  and  then 
return  to  their  work  after  the  explosion.  I  have 
frequently  seen  the  great  cloud  of  Grondone  form 
about  noon,  and  keep  together  until  four  or  five 
o'clock,  and  then,  after  a  few  claps,  give  way  to  a 
small  thunder-storm." 

"We  find  the  following  curious  passage  in  a 
recent  description  of  the  caves  and  grottoes  of  Nor- 
way :  "  A  promontory  of  the  Lyse-Fiord  contains 
a  cavern  really  terrible,  on  account  of  the  meteoro- 
logical phenomena  of  which  it  is  the  scene.  It  is 
well  known  that  there  are  no  rocky  cliffs  of  more 
sinister  aspect  than  those  of  the  Lyse-Fiord.  It  is 
toward  the  fifty-ninth  degree  of  latitude,  at  a  short 
distance  to  the  eastward  of  the  port  of  Stavanger, 
that  this  arm  of  the  sea  opens.  It  is  a  prodigious 
ditch,  twenty-five  miles  or  so  in  length,  shut  in 
between  two  walls  of  sharp-pointed,  perpendicular 
rocks  of  the  average  height  of  more  than  half  a 
mile.  No  doubt  the  first  mariner  who  navigated 
the  still,  black  waters  of  this  chasm,  must  have 
proceeded  with  a  certain  feeling  of  horror,  asking 
himself  at  every  turn  if  he  was  not  about  to  see 


132         METEOES   AND   METEOEIO   PHENOMENA. 

some  frightful  old  Norse  deity  start  up  before  Mm. 
Even  now  it  is  not  without  a  shudder  that  one 
penetrates  this  sea-defile,  in  which  the  ancients 
would  have  recognized  the  entrance  to  Hades. 

"  When  the  southwest  wind  blows  rudely,  and 
plunges  by  violent  gusts  into  the  vast  chasm  of 
the  Lyse-Fiord,  a  strange  meteoric  phenomenon 
adds  to  the  terrible  majesty  of  the  scene.  Fifteen 
hundred  feet  above  the  level  of  the  sea,  and  at 
two-thirds  of  the  height  of  the  wall  that  rises  to 
the  southward  of  the  entrance  to  the  gulf,  there 
is  seen  a  flash  of  lightning  leaping,  from  time  to 
time,  from  the  black  rock,  spreading,  then  con- 
tracting, then  expanding,  and  shrinking  again, 
and  dispersing  in  luminous  fringes  before  it 
reaches  the  northern  wall.  This  broad  tongue  of 
fire  advances,  whirling  round  and  round  as  it 
goes,  and  it  is  to  this  rotary  movement  that  the 
apparent  expansions  and  contractions  of  the  light- 
ning are  due.  Rapid  detonations  are  heard  with 
an  increasing  power  before  the  live  flame  leaps 
from  the  rock ;  a  violent  clap  of  thunder  accom- 
panies it,  and  reverberates  in  prolonged  echoes 
through  this  narrow  corridor  of  the  sea.  One 
would  think  that  some  battery,  hidden  behind 
the  cliff,  was  cannonading  some  invisible  casemate 
in  the  opposite  wall." 


EFFECT   OF   THUNDER-STORMS.  133 

During  volcanic  eruptions,  the  clouds  that 
issue  from  the  craters  emit  numerous  flashes  of 
lightning.  These  clouds  are  composed  of  smoke 
and  vapor,  mingled  with  ashes,  and  often  of  ashes 
alone.  In  1631,  an  immense  column  of  smoke 
rose  from  Yesuvius,  and  was  borne  for  a  distance 
of  more  than  one  hundred  and  twenty  miles. 
During  its  passage  it  threw  off  shafts  of  lightning, 
accompanied  with  thunder,  that  killed  several 
persons.  In  another  eruption,  the  cloud,  which 
was  extremely  black  and  composed  of  impalpable 
ashes,  got  as  far  as  the  town  of  Tarentum,  where 
the  lightning  set  fire  to  a  number  of  buildings. 
These  volcanic  thunder-storms  have  also  taken 
place  at  sea.  In  1811,  when  the  island  of  Sabrina 
emerged  from  the  waters  in  the  vicinity  of  the 
Azores,  the  columns  of  dust  and  ashes  that  rose 
from  it  were  furrowed  with  lightning  of  extraor- 
dinary vividness,  according  to  the  statement  of  the 
ship-captain  who  witnessed  the  phenomenon. 

THE   EFFECT   OF  THUNDER-STORMS  ON    SUBTERRANEAN 
WATERS. 

Arago  speaks  of  modifications  that  have  some- 
times taken  place  in  underground  waters  during 
stormy  weather,  in  which  thunder  and  lightning 
play  a  part;  of  springs  that  become  troubled  and 


134         METEORS    AND   METEORIC    PHENOMENA. 

overflow,  even  after  a  great  drought ;  of  deep  wells 
heard  boiling  and  bubbling  noisily  ;  of  fountains 
leaping  from  the  rock  with  sensibly  augmented 
projectile  force.  Yallisneri  has  remarked  that 
the  salsae  and  solfatarae,  or  volcanic  salt  and  sul- 
phur fields,  in  the  vicinity  of  Modena,  announce 
thunder-storms  by  a  sort  of  ebullition,  and  by 
noises  resembling  thunder. 

"  Historians  and  meteorologists,"  says  Arago, 
"mention  local  inundations  the  effects  of  which 
seemed  to  go  far  beyond  what  the  small  quantity 
of  rain  issuing  from  the  clouds,  and  falling  with- 
in a  certain  radius,  could  have  led  any  one  to 
fear."  It  has  rarely  happened  that,  upon  such  oc- 
casions, immense  masses  of  water  have  not  been 
seen  rising  from  the  bowels  of  the  earth,  for  a 
greater  or  less  period  of  time,  from  openings  until 
then  unknown,  or  that  a  violent  thunder-storm 
has  not  been  the  precursor  of  the  phenomenon 
and  probably  its  most  immediate  cause.  Such, 
for  instance,  were  in  every  particular  the  circum- 
stances of  the  inundation  that  in  July,  1688, 
almost  utterly  destroyed  the  villages  of  Kettlevel 
and  Starbottom  in  Yorkshire,  England.  During 
the  storm  an  immense  chasm  formed  in  the  adj  ac- 
cent mountain,  and,  according  to  eye-witnesses, 
the  mass  of  water  that  gushed  from  it  contrib- 


EFFECT   OF   THUNDER-STORMS.  135 

uted,  as  much,  as  the  rain,  to  the  ravages  that 
ensued. 

In  October,  1T55,  according  to  Beccaria,  a 
sudden  inundation  produced  great  destruction  in 
most  of  the  valleys  of  Piedmont.  The  river  Po 
overflowed,  and  the  disaster  was  preceded  by  hor- 
rible thunder,  orrendi  tuoni,  says  the  learned  Ital- 
ian. Everybody  agreed  that  the  principal  cause 
of  the  inundation  was  the  immense  volume  of 
water  which,  during  the  storm,  suddenly  issued 
through  new  openings  from  underground  among 
the  mountains. 

These  local  fractures  of  the  solid  crust  of  the 
globe  would  have  nothing  very  extraordinary 
about  them,  were  it  proven  that,  in  stormy 
weather,  the  water  has  a  tendency  to  seek  the 
clouds,  and  that  this  tendency  manifests  itself  by 
abrupt  outbursts  from  below.  This  is  precisely 
the  conclusion  to  be  drawn  from  observations 
made  on  board  the  packet-ship  New  York  in 
1827.  While  the  storm  raged  around  the  vessel 
in  question,  the  sea  was  in  a  continual  ebullition 
of  such  a  nature  as  to  convey  the  idea  of  subter- 
ranean volcanoes.  Especial  note  was  taken  of 
"  three  columns  of  water  which  leaped  high  into 
the  air,  then  fell  back,  then  leaped  up  again,  and 
once  more  subsided.'7 

7 


136         METEORS   AND   METEORIC   PHENOMENA. 
THE   USEFULNESS   OF   THUNDER-STORMS. 

Science  teaches  us  to  appreciate  the  beneficent 
effects  of  the  thunder-storm,  the  appearance  of 
which  was  once  considered  a  sign  of  celestial  dis- 
pleasure. The  explosions  of  thunder  and  light- 
ning produce  a  profound  modification  in  the  con- 
stituent elements  of  the  atmosphere.  The  gases, 
which  are  held  merely  in  a  state  of  simple  mixture 
in  the  absence  of  the  electric  spark,  are  combined 
by  its  agency  in  such  manner  as  to  form  ne*w  sub- 
stances, that  are  detected  in  various  quantities  in 
rain-water.  Under  certain  circumstances  these 
new  combinations  deposit  the  nitre  that  is  found 
on  the  surface  of  the  soil  in  different  countries. 
The  agricultural  efficacy  of  that  substance  has 
been  known  since  the  days  of  antiquity.  Yirgil 
mentions  it  in  his  "G-eorgics."  Agricultural 
writers  recognize  the  value  of  other  products  of 
the  thunder-storm  in  helping  vegetation.  Each 
electric  discharge  engenders  in  the  atmosphere 
fruitful  principles  of  life,  which  are  drawn  into 
the  soil,  where  the  roots  of  plants  imbibe  them, 
and  so  communicate  a  fresh  glow  to  their  foliage 
and  flowers. 

Thunder-storms,  also,  purify  the  atmosphere. 
The  passage  of  the  lightning  gives  oxygen  more 


THE   USEFULNESS   OF   THUNDEK-STOKMS.        137 

active  properties,  and  transforms  it  into  ozone. 
Although  this  gas  is  but  little  known,  we  are  safe 
in  attributing  to  it  a  very  energetic  agency  in 
destroying  miasma  and  neutralizing  putridities 
that,  in  spreading  throughout  the  atmosphere, 
render  it  unfit  for  respiration,  and  give  rise  to  the 
severest  maladies.  Ozone  may  be  produced  in  the 
laboratory  by  means  of  strong  electric  sparks.  If 
a  bell  glass  be  filled  with  it,  spoiled  meat  and  of- 
fensive dirt  placed  under  it  soon  lose  their  repul- 
sive odor.  All  the  imperceptible  remains  of  or- 
ganic substances  are  consumed  on  coming  into 
contact  with  the  electrified  air,  and  M.  Schoen- 
bein  has  established  the  fact  that  air,  containing  a 
very  small  proportion  of  ozone,  will  disinfect  an 
equal  volume  of  vitiated  atmosphere. 

According  to  recent  researches,  the  hygienic 
conditions  of  several  regions  appear  to  be  in  rela- 
tion to  the  quantity  of  ozone  in  the  atmosphere. 
In  many  observatories,  this  quantity  is  daily  as- 
certained by  means  of  the  variations  of  color  re- 
vealed by  a  chemical  substance.  It  is  probable 
that  important  laws  will  ultimately  be  developed 
from  a  larger  collection  of  facts. 

After  a  thunder-storm,  a  peculiar  odor,  usually 
spoken  of  as  a  smell  of  sulphur,  or  brimstone,  is 
diffused  through  the  atmosphere.  This  smell  is 


138         METEORS  AND   METEOKIO   PHENOMENA. 

due  to  the  presence  of  ozone,  and,  farther  on,  we 
shall  see  how  it  manifests  itself  in  the  haunts  of 
the  great  electric  meteors  that  serve  the  purpose 
of  thunder-storms  in  the  polar  regions. 


CHAPTEE  VI. 

WHIRLWINDS. 


Water-spouts.— Electric    Whirlwinds.— Sand-storms.— Water-spouts   at 
Sea.— Water-spouts  on  Land.— Tornadoes.— Cyclones.— Hurricanes. 


WATER-SPOUTS. 

"  AMONG  the  great  meteors  that  come  to  trou- 
ble the  apparent  order  and  harmony  of  Nature — 
among  the  grand  phenomena  which  carry  terror 
and  desolation  wherever  they  appear,  there  is  one 
which  distinguishes  itself  from  the  rest  by  the 
strange  and  gigantic  forms  it  assumes,  by  the 
outside  forces  that  it  seems  to  obey,  by  the  un- 
known and  apparently  contradictory  laws  that 
appear  to  regulate  it,  and,  to  sum  up,  by  the  dis- 
asters it  occasions.  These  disasters  themselves 
are  accompanied  by  peculiar  circumstances,  so  re- 
markable that  the  cause  of  them  cannot  be  con- 
founded with  that  of  other  meteors  baleful  to 
humanity.  This  meteor,  so  extraordinary,  so 


140         METEORS  AND   METEORIC   PHENOMENA. 

menacing,  and  fortunately  so  rare  in  our  lati- 
tudes, is  the  one  designated  by  the  general  expres- 
sion of  water-spout" 

Such  are  the  words  of  M.  A.  Peltier,  in  his 
"  Observations  and  Experimental  Researches  on 
the  Causes  that  concur  in  the  Formation  of 
Water-spouts." 

The  least  violent  and  least  dangerous  whirl- 
winds are  those  that  are  produced  by  the  meeting 
of  contrary  winds,  and  have  no  other  cause  than 
the  mechanical  impulsion  of  the  forces  set  in  mo- 
tion during  great  atmospheric  disturbances.  Such 
whirlwinds  often  form  in  mountainous  countries, 
where  the  wind  buries  itself  in  the  gorges,  blows 
in  varying  directions,  and  is  sometimes  abruptly 
interrupted  by  obstacles  that  turn  it  aside. 

"  I  have  often  witnessed  these  phenomena  in 
the  Alps,"  says  Kaemtz,  "  but  will  content  my- 
self with  relating  the  following  fact:  A  very 
strong  south  wind  was  blowing  over  the  summit 
of  the  Righi,  and  the  clouds  that  passed  above  my 
head  were  sweeping  in  the  same  direction.  The 
north  wind  was  blowing  toward  Zurich,  and  as- 
cending along  the  northern  slope  of  the  mountain. 
When  it  reached  the  summit,  light  vapors  formed 
and  seemed  to  seek  a  passage  over  the  crest,  but, 
the  south  wind  throwing  them  back,  they  ascended 


WATER-SPOUTS.  141 

toward  the  north,  at  an  angle  of  forty-five  de- 
grees, and  disappeared  at  the  top.  The  struggle 
of  these  two  contrary  winds  lasted  several  hours. 
A  great  number  of  whirlwinds  formed  at  the 
point  where  the  two  winds  met,  and  travellers, 
who  usually  feel  but  little  interest  in  meteoric  phe- 
nomena, were  struck  by  this  singular  spectacle." 

The  terrible  whirlwinds  that  are  met  with 
chiefly  in  the  tropics,  or  accompany  great  thunder- 
storms, often  spring  up  in  the  midst  of  a  calm, 
and  are  probably  produced  by  the  most  formidable 
forces  of  electricity.  The  clouds,  according  to 
Peltier,  are  the  source  of  this  power,  when,  after 
a  rapid  evaporation  in  calm,  warm  weather,  they 
have  retained  the  electricity  that  was  in  the  va- 
pors, and  that,  most  usually,  is  dispersed  through 
the  damp  atmosphere  into  the  soil.  When  the 
clouds,  thus  charged  with  electric  fluid,  and  often 
accumulated  in  enormous  masses,  chance  to  com- 
bine their  forces  with  the  perturbations  of  the  at- 
mosphere, they  act  with  those  that  are  peculiar  to 
them,  and  add  powerful  influences  of  attraction 
and  repulsion  to  the  violent  shocks  of  the  air.  All 
the  observations  that  have  been  made  relative  to 
water-spouts,  tend  to  prove  that  they  are  the 
result  of  a  transformation  of  these  electric  clouds. 

Before  the  appearance  of  these  water-spouts, 


142         METEOKS   AND   METEORIC   PHENOMENA. 

which  are  much  more  frequent  at  sea  than  upon 
the  land,  black,  stormy  clouds  collect,  and  the 
lowermost  one  in  the  series  is  seen  descending  in 
the  shape  of  a  reversed  cone,  the  point  of  which 
approaches  the  ground  or  the  water  in  a  greater 
or  less  degree.  Beneath  this  descending  cloud, 
the  waters  appear  to  be  in  a  state  of  ebullition, 
and  the  vapor  that  issues  from  them  rises  like 
smoke.  On  land,  light  bodies,  such  as  dust,  etc., 
are  carried  upward  and  form  whirlwinds.  Some- 
times the  point  of  the  cone  touches  the  sea,  and 
there  hollows  out  a  grand  circular  depression,  as 
though  a  violent  current  of  air  issued  from  it. 
Less  frequently,  the  waters  are  lifted  up  in  the 
form  of  a  column,  or  an  ascending  cone.  In  the 
midst  of  the  vapor-clouds  that  surround  the  lower 
part  of  the  water-spout,  sheaves  of  water  gush 
upward,  and  fall  again  on  the  outside.  "This 
mass  of  water,"  says  Peltier,  "  raised  in  the  form 
of  a  whirling,  boiling  smoke ;  these  ascending  and 
descending  jets,  seen  from  a  distance,  have  the 
appearance  of  a  thicket,  or  a  hedge,  such  as  Eng- 
lish navigators  are  accustomed  to  call ( the  bush.'  r 
Water-spouts  nearly  always  emit  a  deafening 
noise,  a  strange,  whizzing  sound,  which  increases 
or  diminishes  according  to  the  greater  or  less 
dampness  of  the  ground  over  which  they  pass. 


ELECTKICAL   WHIRLWINDS.  143 

They  are  frequently  accompanied  by  whirlwinds 
in  the  air,  lightning,  thunder,  hail,  and  rain. 

ELECTRICAL  WHIRLWINDS. SAND-STORMS. 

There  have  been  dry,  whirling  storms,  or 
whirlwinds,  that  have  caused  great  destruction, 
without  having  been  preceded  by  any  gathering  of 
opaque  clouds.  Peltier  admits  that  the  invisible 
vapors  collect  in  transparent  clouds  that  may  be 
charged  with  electricity,  like  opaque  clouds,  and 
reproduce  the  same  phenomena. 

On  the  great  deserts,  during  a  dead  calm,  and 
under  a  blazing  sun,  the  sand  sometimes  rises  in 
the  midst  of  electric  whirlwinds,  that  remind  one 
of  a  water-spout.  Piddington,  in  his  "Law  of 
Storms,"  relates  a  very  interesting  summary  of 
observations  made  in  Hindostan  by  Dr.  P.  Bad- 
dely: 

"  My  observations  extended  from  the  warm 
season  of  1847,  the  period  of  my  first  coming  to 
Lahore,  until  1850 ;  here  is  the  result : 

"Sand-storms  are  caused  by  spiral  columns 
of  electric  fluid  passing  from  the  atmosphere  to 
the  ground.  They  have  a  forward  movement,  a 
rotary  movement,  like  the  whirling  storms  at  sea, 
and  a  special  spiral  movement  from  top  to  bottom. 
It  is  probable  that  in  an  extensive  sand-storm, 


144         METEORS   AMD   METEORIC   PHENOMENA. 

most  of  these  columns  move  together  in  the  same 
direction,  and  that,  while  the  tempest  lasts, 
sudden  and  numerous  gusts  take  place  at  in- 
tervals, in  which  the  electric  tension  is  at  its 
maximum. 

"  The  same  phenomena  are  to  be  seen  in  every 
case  of  sand-storm ;  from  those  that  are  but  a  few 
inches  in  diameter,  to  those  that  have  fifty  miles 
and  more  of  extent,  the  phenomena  are  identical. 

"  It  is  a  curious  fact  that  some  of  the  smallest 
sand-storms  that  are  seen  occasionally  in  the 
great  arid  plains  of  this  country  (India)  and  Af- 
ghanistan, above  the  Bolan  Pass,  and  which  are 
called  (  devils  '  in  vulgar  parlance,  are  stationary 
for  a  while,  that  is  to  say,  for  an  hour  or  more, 
and,  during  all  this  time,  the  sand,  or  dust,  and 
other  light  bodies  from  the  ground,  keep  up  their 
whirling  movement  in  the  air.  In  other  cases, 
small  sand-storms  advance  slowly,  and  when  they 
are  numerous  they  move  usually  in  the  same  di- 
rection. Frequently,  birds,  such  as  kites  and  vul- 
tures, soar  above  these  heights,  and  evidently 
follow  the  direction  of  the  column,  as  though  it 
gave  them  pleasure.  I  think  that  the  phenomena 
associated  with  sand-storms  are  identical  with 
those  that  are  presented  by  water-spouts,  in  white 
squalls  at  sea,  and  in  tornadoes  of  every  descrip- 


SAND-STORMS.  145 

tion ;  and  that  they  arise  from  the  same  cause, 
that  is  to  say,  from  movable  columns  of  electri- 
city. 

"  In  1S4Y,  at  Lahore,  desirous  of  satisfying 
my  mind  in  regard  to  the  nature  of  sand-storms, 
I  placed  in  the  open  air,  on  the  roof  of  my  house, 
a  copper  wire  insulated  upon  a  bamboo.  I  led  one 
end  of  the  wire  into  my  room,  and  put  it  in  com- 
munication with  an  electrometer  with  a  golden 
plate  and  a  wire  connecting  with  the  ground.  A 
day  or  two  afterward,  during  the  passage  of  a 
small  sand-storm,  I  had  the  pleasure  of  seeing  the 
electric  fluid  passing  from  one  wire  to  the  other 
in  vivid  sparks,  and  powerfully  affecting  the  elec- 
trometer. The  fact  was,  henceforth,  explained ; 
and  since  that  time  I  have,  by  the  same  means, 
taken  note  of  at  least  sixty  sand-storms  of  differ- 
ent dimensions.  All  of  them  presented  the  same 
phenomena. 

"  I  have  observed  that,  usually,  toward  the 
termination  of  a  storm  of  this  kind,  the  rain  falls 
suddenly,  and  that,  instantaneously,  the  current 
of  electricity  ceases  or  greatly  diminishes ;  when 
it  continues,  it  would  seem  that  it  does  so  only 
in  cases  where  the  storm  is  of  considerable  power, 
and  lasts  for  some  time  afterward." 

The  author  then  gives  an  account  of  his  meth- 


146         METEORS   AND   METEOKIC   PHENOMENA. 

od  of  observing  these  phenomena,  and  afterward 
goes  011  with  his  description  of  whirlwinds : 

"  The  sky  is  clear  ;  not  a  breath  of  air  is  stir- 
ring ;  but  see,  presently  there  is  a  bank  of  clouds 
far  down  the  horizon,  and  you  are  surprised  that 
you  did  not  notice  them  before :  a  few  seconds  go 
by,  and  the  mass  of  cloud  has  covered  half  the 
celestial  hemisphere ;  there  is  no  time  to  lose  ;  it 
is  a  sand-storm,  and  every  one  rushes  hurriedly 
in-doors  to  escape  being  caught  in  it. 

"  The  electric  fluid  continues  to  descend  inces- 
santly along  the  conducting  wire,  while  the  storm 
lasts.  The  sparks  are  often  more  than  an  inch  in 
length,  and  emit  a  dull,  crackling  sound.  Its  in- 
tensity varies  with  the  force  of  the  storm,  and,  a& 
I  said  above,  is  strongest  during  the  sudden  gusts. 

"  One  of  these  storms,  which  took  place  last 
year  in  the  month  of  August,  seemed  to  come  .from 
the  direction  of  Lica,  on  the  Indus,  to  the  west  of 
Lahore.  An  officer  on  the  march,  twenty  miles 
distant  from  Lica,  was  suddenly  enveloped  in  it. 
His  tent  was  swept  away,  and  he  was  thrown 
down  and  nearly  suffocated  by  the  sand.  At 
Lica  the  whirlwind  cracked  the  walls  of  a  solid 
brick  building,  in  which  the  same  officer  had  re- 
cently lodged,  and  tore  up  some  trees  in  the  en- 
virons by  the  roots. 


WATER-SPOUTS   AT   SEA.  147 

"  I  have  repeatedly  tried  to  discover  the  kind 
of  electricity  developed,  and  have  found  that  it  is 
not  invariably  the  same.  Sometimes  it  appears 
to  be  positive,  and  at  others  negative.  It  changes 
during  the  storms." 

WATER-SPOUTS   AT   SEA. 

The  extraordinary  effects  produced  by  these 
tornadoes,  their  strange  destructive  power,  and  the 
singularity  of  their  forms,  prepare  our  minds  to 
comprehend  how  they  were  regarded  in  old  times 
as  evil  spirits,  who,  in  this  prodigious  disguise,  re- 
joiced in  desolating  the  face  of  the  country  and 
spreading  terror  far  and  near.  Superstition,  even 
now,  sometimes  attributes  a  sort  of  personality  to 
these  destructive  meteors,  whose  monstrous  aspect 
and  capricious  movements  vividly  strike  the  im- 
agination. Then  the  latter,  by  the  aid  of  ignorance, 
may  give  birth  to  the  most  absurd  fantasies,  hap- 
pily dispelled  in  our  time  with  ease,  by  the  light 
of  science  and  reason. 

Peltier  has  reproduced  the  following  account 
of  a  whirlwind  seen  by  Dr.  Leymerie  on  the  2d 
of  September,  1804,  on  board  the  Le  Vautour  : 

"  This  vessel  was  coming  from  Cayenne,  steer- 
ing for  the  coast  of  Africa,  and  was  not  far  from 
the  river  Gambia,  when  the  wliirlwind  formed. 


14:8         METEOES   AND   METEOEIC   PHENOMENA. 

Before  its  appearance  there  was  a  dead  calm. 
The  preceding  days  had  been  very  warm,  and, 
since  morning,  the  sky  had  become  covered  with 
heavy  clouds.  The  cutter  was  in  pursuit  of  a 
British  slaver,  when,  all  at  once,  those  on  board  of 
her  saw  a  column  of  water,  about  three  hundred 
feet  in  height,  rise  from  the  sea  to  meet  an- 
other column  (of  vapor),  descending  from  the  bed 
of  clouds  overhead.  At  this  instant,  the  calm 
was  broken  and  the  storm  began  to  rage  furious- 
ly. The  column  in  question  was  not  composed 
of  water  in  its  liquid  state,  but  in  the  condition 
of  very  dense  vapor,  as  had  been  frequently  re- 
marked. This  column  was  luminous  throughout 

o 

its  whole  diameter,  and  had  a  slightly  yellowish, 
or  tawny,  phosphorescent  appearance.  The  sea 
itself  was  blazing  with  light,  and  the  vessel  left 
behind  her  a  long  wake  of  fire.  The  storm  lasted 
for  fourteen  hours,  and  caused  many  disasters  in 
those  waters ! " 

Navigators  frequently  have  recourse  to  their 
guns,  in  order  to  break  the  water-spouts.  When 
the  ball  passes  through  them,  they  are  sometimes 
seen  to  separate  into  two  parts,  which  most  usual- 
ly reunite  very  quickly.  Sometimes,  on  the  other 
hand,  the  ball  simply  dashes  the  water  in  jets  on 
each  side  of  the  column,  without  affecting  it  other- 


WHIRLWINDS   ON   LAND.  149 

wise  in  the  least.  Water-spouts,  as  Peltier  re- 
marks, frequently  offer  a  curious  fact,  which 
would  seem  irreconcilable  with  the  theory  of 
wind  tornadoes  being  the  cause  of  the  phenome- 
non. Many  cone-like  points  start  from  the  clouds 
and  soon  combine  in  one  and  the  same  cylinder. 
It  is  difficult  to  demonstrate  that  different  torna- 
does thus  aggregate  in  a  single  shaft,  while  the 
attractive  forces  of  electricity  may  readily  enough 
determine  this  method  of  uniting.  In  the  same 
manner,  the  cloudy  cone  is  seen  dividing  into 
several  spirals,  which  reunite  and  separate  again, 
a  circumstance  that  sets  aside  the  idea  of  an 
impulsion  received  from  the  tornadoes  of  the 
air. 

WHIRLWINDS   ON  LAND. 

Let  us  now  reproduce  two  accounts  of  water- 
spouts on  land,  that  will  give  an  accurate  idea  of 
this  terrible  meteor.  The  first  was  observed  and 
described  by  the  learned  meteorologist  Professor 
Grossmann : 

"  On  the  25th  of  June,  1829,  about  two  o'clock 
in  the  afternoon,  at  a  point  a  league  below  Treves, 
east-northeast  of  Ruwer  and  Pfalzel,  about  twenty 
degrees  above  the  horizon,  a  phenomenon  showed 
itself  that  struck  a  great  number  of  men  at  work 


150         METEORS    AND    METEORIC   PHENOMENA. 

out  of  doors  with  amazement,  and  kept  them  in 
uneasy  suspense  for  half  an  hour. 

"  A  fall  of  rain  had  taken  place  and  the  sky  had 
remained  covered  with  clouds,  when,  all  at  once, 
from  the  middle  of  a  black  cloud  that  rose  in  the 
east-northeast,  a  luminous  mass  began  to  move 
in  the  opposite  direction  and  rend  it  violently. 
The  cloud  speedily  assumed,  at  the  top,  the  form 
of  a  chimney,  from  which  escaped  a  whitish-gray 
smoke,  mingled  occasionally  with  jets  of  flame,  and 
rising  through  several  openings  with  as  much 
force  as  though,  to  use  the  expression  of  the  look- 
ers-on, it  had  been  driven  by  so  many  bellows. 

a  The  meteor  had  advanced  over  the  vineyards 
of  Disburg  and  opposite  to  Ruwer,  when,  some 
distance  farther  to  the  south,  on  the  right  bank  of 
the  Moselle,  and  completely  in  contact  with  the 
soil,  another  meteor  suddenly  appeared.  It  scat- 
tered the  heaps  of  charcoal  piled  up  around  a 
tree,  threw  down  a  laborer  at  an  adjacent  lime- 
kiln, and  dashed  across  the  Moselle  with  a  terrific 
concussion,  as  though  a  great  many  stones  were 
shaken  together.  The  water  leaped  in  a  column 
high  into  the  air. 

"  Continuing  to  roll  along  with  the  same  up- 
roar, the  meteor,  still  grazing  the  ground,  darted 
across  the  Pfalzel  country,  leaving  everywhere  be- 


WHIRLWINDS   ON   LAND.  151 

hind  it  the  most  evident  traces  of  its  zigzag  route 
in  the  grain-fields  and  vegetable-patches.  Part 
of  the  crops  was  totally  destroyed,  part  was  beaten 
down  and  torn  to  pieces,  and  part  whirled  away 
into  the  air. 

"  Many  women  fainted  with  terror  as  the  me- 
teor passed  near  them,  and  others,  who  were  far- 
ther off,  hid  themselves  or  fled,  shrieking  that  the 
'  fields  were  all  on  fire ! '  Two  laborers,  who  had 
climbed  a  tree,  watched  the  meteor  along  its  en- 
tire course ;  a  third  had  even  the  bold  idea  to  fol- 
low it,  which  it  was  easy  to  do,  at  the  ordinary 
walking  gait.  At  length,  in  one  of  its  zigzag 
movements,  it  suddenly  enveloped  him.  He  felt 
himself  at  one  moment  violently  jerked  forward, 
at  another  tossed  up.  He  then  bent  down,  bracing 
himself  strongly  on  the  ground,  with  his  working- 
tools  ;  but  he  was,  nevertheless,  prostrated.  The 
tornado,  however,  left  him,  and  passed  on  its  way. 
The  man  could  recollect  no  particular  impression 
affecting  his  smell  or  taste,  but  merely  a  deafening 
noise.  He  affirms  that  there  were  two  currents  of 
air,  the  one  rising  obliquely,  carrying  up  with  it 
the  stalks  and  stems  of  the  grain,  along  with  other 
light  bodies,  and  the  second  operating  in  a  con- 
trary direction. 

"  The  track  that  the  meteor  had  opened  for  it- 


152         METEORS   AND  METEORIC   PHENOMENA. 

self  across  the  country  was,  according  to  different 
statements,  from  ten  to  eighteen  paces  in  breadth 
and  about  twenty-five  hundred  paces  in  length. 
Its  shape  was  almost  conical,  and  its  color  was, 
at  one  moment,  a  grayish-white  or  yellow,  at  an- 
other a  dark-brown,  but  most  of  the  time  a  fiery 
red.  The  first  meteor  remained  in  the  air  above 
the  second,  and  followed  a  nearly  parallel  route, 
going  toward  the  north.  For  about  eighteen 
minutes  it  presented  a  large  mass  of  whitish-gray 
cloud,  which  repeatedly  seemed  to  vomit  flame- 
colored  smoke,  and,  when  seen  at  the  distance  of 
about  a  mile  and  a  half,  had  the  form  of  a  serpent 
about  one  hundred  and  forty  paces  long,  with  its 
head  to  the  north-northeast  and  its  tail  in  the 
opposite  quarter. 

"  In  eight  or  ten  minutes,  the  tail  had  already 
changed  its  position  by  bending  downward.  Just 
at  the  moment  when  it  was  about  to  touch  the 
head,  the  whole  phenomenon  disappeared,  and 
the  lower  meteor  vanished  at  the  same  instant, 
without  any  detonation  from  either  of  them,  as  an 
eye-witness  affirms ;  but,  with  this,  a  strong  smell 
of  sulphur  spread  over  the  whole  country.  Near- 
ly at  the  same  moment,  a  storm  burst  forth  among 
the  woods  situated  to  the  north-northwest  of  the 
place  where  the  meteor  had  appeared,  and  was 


THE   TORNADO   OF   MONVILLE.  153 

accompanied  by  a  fall  of  extremely  large  hail- 
stones. 

"  The  sun  was  not  seen  during  the  whole  of 
this  time,  as  most  of  the  spectators  declare,  and 
there  was  not  a  breath  of  wind. 

"  The  upper  meteor  was  seen  from  Cassel,  Gut- 
weiler,  and  other  places,  as  also  at  Treves.  It 
seemed  to  descend  from  the  heights  of  Hoch- 
wald." 

THE   TORNADO   OF  MONVILLE. 

The  tornado  of  Monville  and  Malaunay  pro- 
duced still  more  fearful  effects.  The  description, 
incorporated  in  the  Comptes  Rendus  of  the 
French  Academy  of  Sciences,  has  been  summed 
up  by  Professor  Daguin,  of  Toulouse,  as  follows, 
in  his  "  Treatise  of  Physics  "  : 

"  On  the  19th  of  August,  1845,  a  violent  south 
wind  prevailed  in  the  environs  of  Rouen.  In 
the  afternoon,  a  gust  from  the  southwest,  driving 
some  very  dark  clouds  before  it,  met  the  southern 
current,  and  formed  a  strong  whirlwind,  with  a 
sidelong  movement  that  tore  up  a  hundred  and 
eighty  bulky  trees,  twisting  and  wrenching  nearly 
all  of  them,  and  throwing  down  a  drying-house 
belonging  to  an  adjacent  factory.  At  the  same  mo- 
ment, there  was  a  heavy  shower  accompanied  with 


154:         METEOES   AND   METEOEIO   PHENOMENA. 

thunder  and  hail.  However,  there  was  no  tornado 
as  yet,  properly  speaking  ;  but,  after  receding  to  a 
distance  and  traversing  some  twenty-five  miles, 
the  storm  suddenly  returned  into  the  valley  near 
Malaunay  and  Monville,  passing  through  a  wood, 
the  trees  in  which  it  broke  off  close  to  the  ground. 
At  that  moment,  an  enormous  cone,  of  sharply-de- 
fined outline  and  as  black  as  coal-smoke,  was  seen  to 
assume  shape.  The  top  of  it  was  of  a  reddish-yel- 
low, while  it  emitted  flashes  of  lightning  and  a 
heavy  rumbling  sound.  In  a  few  seconds,  the  tor- 
nado hurled  itself,  with  appalling  velocity  and  by 
zizag  motion,  through  three  considerable  spin- 
ning-mills in  succession,  crushing  them  and  all  the 
working-people  in  them.  The  roofs  were  swept 
off,  and  not  one  stone  left  on  another.  The  looms 
were  twisted,  the  heavy  pieces  shattered,  chiefly, 
too,  where  there  were  ponderous  masses  of  metal. 
The  trees  in  the  vicinity  were  flung  down  in  ev- 
ery direction,  riven  and  dried  up  for  a  length  of 
from  six  to  twenty  feet  and  more.  While  clear- 
ing away  the  ruins,  in  the  attempt  to  rescue  the 
unfortunate  people  buried  beneath  them,  it  was 
noticed  that  the  bricks  were  burning  hot.  Planks 
were  found  completely  charred,  and  cotton  burned 
and  scorched,  and  many  pieces  of  iron  and  steel 
were  magnetized.  Some  of  the  corpses  showed 


THE  TORNADO  OF  MONVILLE.        155 

traces  of  burning,  and  others  had  no  visible  cuts 
or  contusions,  but  seemed  to  have  been  killed  by 
lightning.  Workmen  who  were  hurled  into  the 
surrounding  fields,  all  agreed  in  saying  that  they 
had  seen  vivid  flashes  and  had  noticed  a  strong 
smell  of  sulphur.  Persons  who  happened  to  be 
on  the  adjacent  heights,  alleged  that  they  saw  the 
factories  wrapped  in  flames  and  smoke  as  the  cloud 
enveloped  it.  The  breadth  of  the  belt  laid  waste 
by  the  tornado  was  seven  hundred  and  fifteen  feet 
on  the  level  of  Malaunay,  less  than  one  and  a 
half  miles  from  the  point  where  its  ravages 
began,  nine  hundred  and  ninety-five  feet  in  the 
middle,  and  one  hundred  and  ninety-five  feet  near 
Cleres,  where  the  cloud  disappeared.  The  length 
of  the  belt,  as  the  bird  flies,  was  about  ten  miles. 
"  One  really  very  remarkable  circumstance  is, 
that  debris  of  all  kinds,  such  as  slate,  glass, 
planking,  and  pieces  of  wood-work,  mingled  with 
cotton,  fell  near  Dieppe,  at  a  distance  of  from 
fifteen  to  twenty-three  miles  from  the  scene  of  the 
catastrophe.  These  various  objects  were  beheld 
in  the  air  by  several  persons,  who  mistook  them 
for  the  leaves  of  trees,  so  high  were  they  above 
the  ground.  Among  the  scattered  fragments 
carried  thus  far,  was  a  scantling  more  than  a  yard 
long,  five  inches  wide,  and  half  an  inch  thick. 


156         METEORS   AND   METEORIC   PHENOMENA. 

Happily,  all  such  whirlwinds  are  not  so  destructive 
as  the  one  described." 

"When  a  thunder-storm  changes  to  a  whirlwind, 
the  sound  of  the  thunder  ceases  at  once.  The 
electric  discharges  are  effected  through  the  de- 
pressed clouds,  and  the  trees  that  stand  in  the 
track  of  the  meteor.  These  trees,  when  traversed 
by  the  electricity,  are  dried  up  in  a  moment,  and 
the  whirl  breaks  them  instead  of  tearing  them  up. 
The  enormous  meteor  of  this  kind  that  laid  waste 
the  parish  of  Chatenay,  on  the  18th  of  June,  1839, 
in  this  way  destroyed  the  plantations  of  trees  in 
the  valley  lying  "between  the  hills  of  Ecouen  and 
the  eminence  of  Chatenay.  "Fifteen  hundred 
feet  of  trees,"  says  Peltier,  "  had  evidently  served 
as  conductors  to  masses  of  electricity,  and  to  con- 
tinual, incessant  discharges  of  lightning.  The 
temperature,  greatly  increased  by  this  flow  of  the 
electric  fluid,  instantaneously  vaporized  all  the 
moisture  in  these  vegetating  conductors,  and  this 
vaporization  caused  every  one  of  them  to  split 
lengthwise." 

TORNADOES   PROPER. 

The  hurricane  -  storms^  or  cyclones,  during 
which  the  wind  blows  with  extraordinary  violence, 
veering  at  a  leap,  more  or  less  suddenly,  from  one 


TORNADOES   PEOPEE.  157 

point  of  the  horizon  to  the  other,  are  also  classed 
among  those  terrific  phenomena,  the  whirling 
motion  of  which  seems  ascribable  to  an  immense 
electric  action.  All  the  descriptions  that  have 
been  given  of  them  go  to  show  that  these  meteors 
are  produced  like  those  last  described — by  beds  of 
thunder-clouds. 

The  tornadoes  of  the  western  coast  of  Africa 
are  sometimes  rectilinear  gales  of  wind,  like  the 
pamperos  of  South  America,  and  the  arched 
squalls  of  the  straits  of  Malacca,  "  which  rise," 
says  Horsburgh,  in  his  "  East  India  Sailing  Direc- 
tions," "  with  a  black  arch  of  clouds  ascending 
rapidly  from  the  horizon  to  the  zenith,  and 
scarcely  giving  time  to  take  in  sail."  But,  in 
most  cases,  these  tornadoes  are  veritable  "  cy- 
clones in  miniature,"  as  Piddington  correctly  calls 
them. 

"  On  the  approach  of  a  tornado,"  says  Hop- 
kins, in  his  work  on  atmospheric  disturbances,  u  a 
dense  mass  of  clouds  gathers  in  the  east  and  on  the 
horizon ;  it  is  accompanied  by  frequent,  dull,  but 
brief  noises,  that  remind  one  of  the  growling  of 
some  wild  animal.  This  bank  of  clouds  gradually 
covers  a  part  of  the  horizon,  and  extends  from 
there  to  the  zenith  ;  but  generally,  beforehand,  a 
small,  radiating  arch,  of  well-defined  outline,  ap- 


158         METEOES   AND   METEOEIO   PHENOMENA. 

pears  on  the  edge  of  the  horizon,  and  continually 
increases.  Long  before  it  reaches  the  ship,  one 
hears  the  whizzing  of  the  wind,  which  produces 
nearly  as  much  noise  as  the  roaring  of  the  thunder 
when  it  seems  to  rend  the  clouds  apart  with  vio- 
lence. The  course  of  the  gale  is  distinctly  marked 
by  the  line  of  foam  that  it  raises." 

The  following  description,  given  by  Mr.  Min- 
graden  in  the  Quarterly  Journal  of  Science,  1837, 
completes  these  observations  :  "  When  the  torna- 
do is  approaching,  it  is  remarked  that  the  rain 
seethes  down  in  torrents,  and  that  the  flashes  of 
lightning  part  the  clouds  in  such  profusion  that 
they  resemble  continual  discharges  of  electric 
fluid.  When,  however,  the  squall  has  got  within 
half  a  mile  of  the  ship,  these  electric  appearances 
cease  altogether.  The  rain  only  continues  the 
same.  When  the  tornado  passes  over  the  vessel, 
there  is  a  dull  crackling  distinctly  heard  in  the 
rigging.  It  is  occasioned  by  the  descent  of  the 
electric  fluid  along  the  masts,  the  tips  of  which 
serve  to  attract  it ;  and  I  have  been  told  that,  when 
this  phenomenon  occurs  at  night,  every  part  of 
the  rigging  seems  illuminated.  When  the  squall 
has  passed  the  vessel  about  half  a  mile,  the  same 
signs  that  characterized  its  approach  from  the 
land  reappear  exactly,  and  before  attaining  the 


TORNADOES    PROPER.  159 

same  distance  from  the  ship.  The  lightnings 
again  descend  in  continuous  sheets,  and  in  such 
abundance  that  they  resemble  the  torrents  of  rain 
that  accompanied  the  squall.  These  squalls  occur 
every  day  during  a  certain  part  of  the  year  termed 
the  harmattan l  season.  The  jet  of  black  clouds, 
coming  from  the  mountains,  begins  to  appear 
about  nine  o'clock  in  the  morning,  and  reaches 
the  sea  about  two  o'clock  in  the  afternoon. 
Another  singular  fact  follows  these  tornadoes. 
After  having  whirled  over  an  extent  of  eight  or 
nine  leagues,  they  disappear,  and  flashes  of  light- 
ning are  beheld  darting  up  from  the  sea.  The  vio- 
lence of  the  wind  during  the  storm  is  excessive. 

"  The  circular  motion  of  the  air  at  the  outset  of 
these  tornadoes  is  indicated  by  the  whirling  about 
of  the  leaves  and  straws  that  are  caught  up  by  it. 
These  meteors  precede  the  rainy  season,  and  are 
more  or  less  violent,  according  to  the  state  of  the 
atmosphere.  Ordinarily,  they  last  but  a  little 
while,  and  are  always  followed  by  a  heavy  shower, 
which  revives  vegetation,  and  freshens  the  atmos- 
phere, that  had  been  made  stifling  by  the  blazing 
heat.  Hence,  every  one  feels  a  vivifying  sensation 
of  enjoyment  after  they  are  over." 

1  The  harmattan  is  a  dry  wind  that  blows  from  the  interior  of 
Africa  toward  the  Atlantic,  principally  in  the  months  of  Decem- 
ber, January,  and  February. 


160         METEORS   AND   METEORIC    PHENOMENA. 
CYCLONES. HURRICANES. 

Piddington  relates  the  meeting  of  two  torna- 
does, which,  in  violence,  could  be  compared  to 
cyclones.  The  phenomenon  was  observed  at 
Charleston,  in  South  Carolina,  May  2,  1761,  at 
two  o'clock  in  the  afternoon : 

"  The  tornado  crossed  the  Ashley  River,  and 
swooped  down  upon  the  shipping  at  Rebellion 
Wharf,  with  such  fury  as  to  threaten  the  destruc- 
tion of  the  entire  fleet.  From  the  city  it  was 
seen  coming  at  first  rapidly  toward  Wappo  Creek, 
like  a  column  of  smoke,  with  a  very  irregular  and 
tumultuous  movement.  The  quantity  of  vapor 
that  composed  this  column,  and  its  prodigious 
velocity,  produced  so  intense  a  commotion  that  it 
agitated  Ashley  River  to  its  depths,  and  left  the 
channel  bare.  The  ebb  and  flow  made  the  ship- 
ping float  off  to  a  great  distance.  When  it  struck 
the  river,  it  made  a  noise  like  continuous  thunder ; 
its  diameter,  at  that  moment,  was  estimated  at  fif- 
teen hundred  feet,  and  its  height,  as  seen  from 
Charleston,  at  twenty-five  degrees.  It  was  met,  at 
White  Point,  by  another  whirlwind,  which  descend- 
ed Cooper  River,  but  was  not  equal  to  the  first. 
When  they  came  together,  the  commotion  in  the 
air  was  much  greater  still;  the  foam  and  the 


CYCLONES.  101 

vapor  seemed  to  be  thrown  to  the  height  of  forty 
degrees,  while  the  clouds,  that  hurried  from  all 
directions  toward  that  point,  seemed  to  rush 
thither  and  whirl  about,  at  one  and  the  same  time, 
with  incredible  velocity.  The  meteor  then  darted 
upon  the  shipping  in  the  roadstead,  and  reached 
them  in  three  minutes,  although  the  distance  was 
nearly  six  miles.  Out  of  forty-five  vessels,  five 
were  sunk  on  the  spot ;  the  State  ship  Dolphin 
and  eleven  others  were  dismasted.  The  damage, 
estimated  at  more  than  £200,000,  was  done  in  a 
moment,  and  even  the  vessels  that  sank  were 
swallowed  up  so  rapidly  that  the  people  who  were 
below  had  scarcely  time  to  scramble  up  on  deck. 
The  whirlwind  of  Cooper  River  changed  the 
course  of  the  one  that  came  from  Wappo  Creek, 
which,  had  it  not  been  for  that,  would,  pro- 
ceeding in  the  same  direction,  have  swept  away 
the  city  of  Charleston  before  it  like  so  much 
straw. 

"This  terrible  column  was  first  perceived 
about  noon,  at  more  than  fifty  miles  west-south- 
west of  the  roads.  It  destroyed  every  thing  in  its 
way,  making  a  complete  avenue  when  it  passed 
through  the  woods.  The  loss  of  the  five  ships 
was  so  sudden  that  it  is  not  known  whether  it 
was  the  weight  of  the  column  of  wind,  or  the 


162         METEOKS  AND   METEOEIC   PHENOMENA. 

mass  of  water  driven  upon  them,  that  made  them 
go  down." 

It  is  near  the  Antilles,  in  the  Gulf  of  Mexico, 
and  in  the  Indian  Seas,  that  the  most  disastrous 
hurricanes  burst  forth.  These  are  the  appalling 
cyclones,  during  which  Nature  seems  to  return  to 
original  chaos. 

"  Sometimes,"  says  an  old  author,  quoted  in 
the  article  on  "  ^Eolian  Researches  "  in  the  Nauti- 
cal Magazine  for  1841,  "  sometimes,  toward  that 
side  of  the  horizon  from  which  the  storm  comes, 
is  first  seen  something  like  a  cloud  blazing  in  the 
most  astonishing  manner  ;  and  some  of  these  hur- 
ricanes and  whirlwinds  have  appeared  so  terrific 
as  to  convey  the  idea  that  the  entire  atmosphere 
and  sea  were  in  one  tremendous  blaze.  Captain 
Prowd,  of  Stepney,  in  one  of  his  voyages  to  the 
East  Indies,  encountered  a  storm  of  this  kind,  and 
left  some  particulars  concerning  it,  which  I  have 
extracted  from  his  journal.  The  sea  was  agitated 
throughout,  and  what  was  the  most  astonishing 
and  terrifying  circumstance  was,  that  the  sky  be- 
came surprisingly  red  and  inflamed  on  the  north- 
ern part  of  the  horizon.  The  sun  was  then  at  the 
zenith.  Signs  of  a  tempest  were  recognized  in 
these  appearances,  and  the  storm  came,  as  had 
been  foreseen.  As  the  darkness  grew  thicker,  the 


HURRICANES.  163 

violence  of  the  wind  increased  until  it  attained 
the  proportions  of  an  awful  hurricane.  At  one 
o'clock  in  the  morning  it  beat  with  such  force  that 
it  was  impossible  to  keep  a  sail  on  the  vessel. 
Seven  men  could  scarcely  steer.  The  whole  at- 
mosphere, the  sky,  and  the  sea,  in  their  wrath, 
seemed  but  one  mass  of  fire." 

An  official  account  of  the  fearful  hurricane 
that  devastated  Guadeloupe  on  the  25th  of  July, 
1825,  contains  the  following  passage : 

"  The  wind  at  the  moment  of  its  greatest  in- 
tensity seemed  luminous ;  a  silvery  flame  streamed 
through  the  chinks  in  the  walls,  the  key-holes,  and 
other  openings,  and  made  one  think,  in  the  dark- 
ness inside  of  the  houses,  that  the  heavens  were 
on  fire." 

Sometimes,  a  dense  bank  of  clouds  of  mena- 
cing blackness  is  seen  on  the  side  of  the  horizor 
from  which  the  cyclone  comes.  Sheets  of  light 
ning  issue  from  it,  the  "  terrible  magnificence  * 
of  which,  according  to  Piddington,  recalls  the 
splendors  of  the  aurora  borealis.  At  the  same 
time,  the  sea  becomes  covered  with  phosphores- 
cent coruscations  that  fill  the  sombre  night  with 
a  pale  radiance;  while,  during  the  daytime,  a 
blood-red  sky  spreads  its  sinister  hue  over  the 
whole  horizon.  A  profound  calm  nearly  always 


164:         METEORS   AND   METEORIC   PHENOMENA. 

precedes  the  hurricane,  which  is  also  announced  by 
"  the  distant  moaning  of  the  elements,  as  though 
the  winds  were  engulfing  themselves  in  a  vault. 
These  remote  rumblings  recall  the  sound  of  a 
thunder-storm  heard  in  caverns." 

The  sea  assumes  a  murky  color,  breaks  foam- 
ing on  the  shore,  and  lifts  itself  sometimes  in 
enormous  tidal-waves  (  "  the  heavings  of  the  tem- 
pest " ),  produced  by  the  approach  of  the  cyclone. 
The  elevation  of  the  usual  level  of  the  waters, 
which  is  almost  always  the  sign  of  violent  storms 
or  heavy  rains,  often  causes  inundations  of  low 
shores  beaten  by  the  hurricane. 

The  diameter  of  this  immense  meteor  varies 
from  fifty  to  one  hundred  miles,  and  sometimes 
more.  The  disk  of  whirling  air  has  probably 
never  more  than  from  one  to  ten  miles  of  vertical 
height.  Placed  upon  a  summit,  like  the  Peak  of 
Teneriffe,  the  observer  would  see  it  pass  below 
him,  as  travellers  among  the  Alps  often  view 
thunder-storms  devastating  the  valleys  at  their 
feet.  In  most  of  these  cases,  the  disk  of  the 
cyclone  is  so  thin  that  the  sky  can  be  distinctly 
seen  through  the  black  masses  of  cloud.  Pidding- 
ton  quotes  the  following  extracts  from  the  log  of 
two  sea-captains : 

"We  observed  one  very  remarkable  circum- 


HURRICANES.  165 

stance :  while,  all  around  the  horizon,  there  ap- 
peared a  bank  of  dense  clouds,  the  sky  at  the 
zenith  was  so  perfectly  clear  that  we  could  see  the 
stars ;  and  every  one  on  board  noticed  above  the 
mizzen-mast-head  a  meteoric  light  of  peculiar 
brightness. 

"  While  we  were  lying-to,  the  clouds  were  rent 
asunder,  and  the  sun,  gleaming  over  the  whole 
surface  of  the  water,  gave  the  foam  a  tinge  as 
white  as  snow,  and  then  as  richly  colored  as  the 
rainbow  in  all  its  shadings." 

Numerous  observations  tend  to  prove  that  the 
disk  of  the  storm  is  nearly  always  inclined  for- 
ward. While  the  front  of  the  hurricane  is  at- 
tacking the  land  or  the  sea,  the  rear  rises,  and 
shows  long  trains  of  clouds,  which  are  seen  whirl- 
ing about  in  the  most  extraordinary  manner. 
Strong  discharges  of  electricity  take  place  at  the 
same  moment  and  announce  the  termination  of 
the  cyclone. 

The  typhoons  of  the  India  Ocean  are  preceded 
by  the  same  signs,  and  accompanied  by  the  same 
phenomena,  as  the  cyclones  of  the  Atlantic,  from 
which  they  differ  in  some  unimportant  particu- 
lars only.  In  the  China  seas,  the  strongest  of 
these  hurricanes  are  termed  "  iron  whirlwinds." 

The  frightful  sea  that  they  heave  up  ;  the 


166         METEOKS  AND   METEORIC   PHENOMENA. 

tremendous  violence  of  the  wind,  blowing  in  op- 
posite directions  from  one  side  to  the  other  of  the 
disk ;  the  dangerous  calm  that  reigns  at  the  cen- 
tre, and  leaves  the  ship  motionless  under  the  shock 
of  monstrous  billows ;  the  cataracts  of  rain ;  the 
terrific  din  of  the  elements, — all  unite  to  render 
the  struggle  hopeless  for  the  seaman.  It  is  es- 
pecially at  night,  in  the  midst  of  profound  dark- 
ness, under  the  livid  lightnings,  or  in  the  strange 
phosphorescent  glare  which  sometimes  envelops 
the  ship,  that  the  horror  of  the  spectacle  defies 
description.  "  If  the  winds  are  let  loose  in  a 
tempest,"  says  Thomas  Fuller,  an  old  seaman, 
"they  become  raging  madmen  in  a  hurricane." 
In  his  voyage  to  the  Isle  of  France,  Bemardin  de 
Saint-Pierre  gives  a  very  exact  description  of  a 
hurricane  that  he  witnessed : 

"  On  the  23d  of  December,  in  the  morning, 
the  wind  being  at  the  southwest,  the  weather  be- 
gan to  work  up  for  a  gale.  Clouds  accumulated 
on  the  summit  of  the  mountains.  They  were 
dark,  olive,  and  copper  colored.  One  long  upper 
band  that  remained  motionless  was  noticed.  The 
clouds  lower  down  were  in  swift  motion.  The 
sea  broke  with  a  great  noise  on  the  reefs.  Many 
marine  birds  sought  refuge  on  land  and  came  fly- 
ing in  from  the  open  expanse.  The  domestic  ani- 


HURRICANES.  167 

mals  seemed  uneasy.  The  air  was  heavy  and 
warm,  although  the  wind  had  not  fallen.  In 
view  of  all  these  signs  that  foretold  a  hurricane, 
everybody  hastened  to  prop  and  brace  his  dwell- 
ing and  carefully  to  close  all  the  openings. 

"About  ten  o'clock  in  the  evening  the  tempest 
came  on.  First,  there  were  fearful  gusts,  followed 
by  moments  of  appalling  calm,  in  which  the  wind 
seemed  to  recruit  its  strength.  Thus  it  continued 
with  augmenting  violence  during  the  night.  My 
cottage  having  been  badly  shaken,  I  moved  to  an- 
other shelter.  My  hostess  was  in  tears  for  fear 
that  her  house  would  be  destroyed.  ~No  one  went 
to  bed.  Toward  morning,  the  wind  having  be- 
come still  more  violent,  I  saw  that  a  whole  front 
of  the  surrounding  palisade  was  about  to  fall,  and 
that  a  portion  of  our  roof  was  lifting  at  one  cor- 
ner. So,  with  some  boards  and  rope,  I  prevented 
the  damage.  In  crossing  the  yard  to  give  some 
orders,  I  several  times  expected  to  be  thrown 
down.  I  could  see  walls  falling  in  the  dis- 
tance, and  fragments  of  ruin  carried  away,  as 
though  they  were  cards.  Rain  fell  at  eight 
o'clock  in  the  morning,  but  the  wind  did  not 
cease.  It  was  driven  horizontally  with  so  much 
violence,  that  it  entered  in  jets  at  the  smallest 
orifices. 


168         METEORS  AND   METEORIC   PHENOMENA. 

"  At  eleven  o'clock,  the  rain  fell  in  torrents. 
The  wind  subsided  a  little,  and  in  ravines  of  the 
mountains  on  all  sides  prodigious  cascades  were 
formed.  Pieces  of  rock  detached  themselves,  and 
fell  with  a  noise  like  that  of  a  cannon,  and  as  they 
rolled  down  they  forced  great  gaps  in  the  woods. 
The  streamlets  overflowed  in  the  plain,  which  was 
like  a  sea. 

"  At  one  in  the  afternoon,  the  wind  leaped 
round  to  the  northwest,  and  drove  the  foam  of 
the  sea  in  huge  clouds  upon  the  land.  It  threw 
the  vessels  in  port  upon  the  shore,  and  they  kept 
firing  guns  of  distress,  but  it  was  impossible  to 
help  them.  By  those  new  concussions  the  houses 
were  shaken  in  another  direction  and  with  nearly 
equal  violence.  The  winds  then  made  the  com- 
plete round  of  the  horizon,  as  is  usually  the  case, 
and,  after  that,  everything  became  quiet  again. 

"  A  great  many  trees  were  blown  down  and 
bridges  carried  away.  Not  a  leaf  was  left  in  the 
gardens,  and  even  the  grass,  that  strong,  coarse, 
tropical  herbage,  appeared  in  some  places  to  have 
been  shaved  off  close  to  the  ground." 

Although  these  terrible  meteors  are  chiefly 
frequent  in  the  torrid  zone,  they  also  appear  some- 
times in  our  temperate  climates,  on  the  Atlantic 
and  Mediterranean  coasts.  We  shall  presently 


HURRICANES.  169 

Bee  how  our  meteorological  observations  can  fol- 
low them  in  their  course,  and  warn  the  places 
menaced  by  them  in  good  time. 

"  These  convulsions  of  Nature,"  says  Peltier, 
"seem  necessary  to  reestablish  the  equilibrium 
of  the  atmosphere,  and  often,  notwithstanding  the 
terrors  that  they  inspire,  the  inhabitants  of  the 
countries  that  they  ravage  invoke  them  with  all 
their  hearts. 

"  Dense,  stagnant  fogs,  that  cause  disease,  are 
dispersed  by  the  storm ;  abundant  rains  reani- 
mate life  and  spread  freshness  on  all  sides ;  the 
air  becomes  pure  and  light ;  renewed  by  the 
electric  action  of  these  tempests,  it  restores  vigor 
to  men  and  animals,  exhausted  by  the  overwhelm- 
ing heat  of  the  burning  season,  and  gives  back 
their  brilliant  verdure  to  the  wilting  plants.  To 
the  commotion  of  the  hurricane,  the  howling  tem- 
pest, the  torrents  of  rain,  the  lightning,  and  the 
thunder,  succeed  the  serenity  of  the  fine  weather, 
the  calm,  the  pure  light,  and  the  beauty  of  an  in- 
comparable spring." 


CHAPTEE  YII. 

RAINBOWS.— CROWNS    AND    HAL  OS. 


Description  of  the  Kainbow.— Play  of  Light  in  the  Drops  of  Water.— 
Varied  Appearances  of  the  Arch.— Supplementary  Arcs.— The  Cir- 
cles of  Ulloa.— Crowns.— Colored  Arcs.— Parhelia.— White  Arcs.— 
Anthelia.— The  Halo  of  Clere". 


DESCRIPTION  OF  THE  KAINBOW. 

"  0  Thou,  Light,  eternally  one !  dwell  there,  on  high,  with  the 
Being  eternally  one!  Thou,  0  changing  Color!  descend  in 
friendly  guise  to  man ! " — SCHILLER. 

!N"o  scene  that  Nature  presents,  better  symbol- 
izes this  fine  thought  of  the  poet  than  the  mag- 
nificent arch,  painted  by  the  sun  upon  the  dark 
clouds  of  a  retiring  tempest.  In  all  ages,  the 
rainbow  has  charmed  the  imaginations  and  awak- 
ened a  feeling  of  hope  and  consolation  in  the 
minds  of  men.  The  Hebrew,  impressed  with  the 
remembrance  of  the  former  floods  that  came  upon 
the  earth,  felt  his  soul,  that  had  been  disquieted  by 
the  thought,  resume  all  its  serenity  as  he  beheld 


DESCRIPTION   OF   THE   RAINBOW.  171 

the  bow  of  promise.  For  him  it  was  the  token 
of  Jehovah's  pardon. 

The  gay  fancy  of  the  Greeks  made  the  rain- 
bow the  presage  of  happy  tidings  to  the  earth, 
the  goddess  Iris,  the  messenger  of  Olympus,  ac- 
cording to  their  creed,  left  her  transparent  scarf 
floating  on  the  clouds. 

Ingenious  fiction  vanished  at  the  approach  of 
science,  and  the  explanation  of  the  rainbow  is, 
to-day,  one  of  the  most  complete  parts  we  have 
of  the  physical  theory  of  light.  It  is  to  Kepler, 
whose  genius  was  prolific  in  so  many  directions, 
that  we  are  indebted  for  the  discovery  of  the  first 
causes  of  the  phenomenon ;  he  put  it  on  record, 
although  very  briefly,  in  a  letter  written  by  him 
in  1601.  ISTewton  studied  these  causes  with  all 
the  rigor  of  geometrical  calculation,  and  was 
enabled  to  render  an  account  of  all  the  different 
modifications  observed  in  the  rainbow.  After 
having  calculated  its  dimensions,  he  verified  the 
correctness  of  his  observations  by  actual  experi- 
ment. 

We  never  see  the  rainbow  excepting  when 
standing  with  our  backs  toward  the  sun,  the  space 
in  front  being  traversed  by  a  shower  of  rain,  a  cas- 
cade, or  a  simple  jet  of  water.  When  the  sea  is 
agitated  by  a  violent  wind,  and  the  sun's  rays  strike 


172         METEORS   AND   METEOKIC    PHENOMENA. 

the  spray  of  the  billows,  rainbow  curves  and  arcs 
are  often  produced  upon  it. 

Usually,  the  phenomenon  consists  of  two  con- 
centric arches,  with  a  considerable  interval  between 
them.  The  centre  of  these,  as  it  is  easy  to  prove, 
corresponds  with  that  point  in  the  heavens  where 
the  shadow  of  the  observer's  head  would  fall. 
The  interior  curve,  which  is  the  oftenest  seen,  pre- 
sents a  series  of  prismatic  radiations,  arranged  in 
such  wise  that  the  violet  falls  inside,  and  the  red 
upon  the  outside.  In  the  external  curve,  the  colors 
of  which  are  much  weaker,  the  order  of  the  series 
is  reversed.  Sometimes  three  bows  are  seen,  but 
this  occurs  very  rarely.  The  third,  of  an  extreme- 
ly pale  hue,  then  presents  colors  arranged  in  the 
same  order  as  in  the  first  instance. 

The  dimensions  of  these  bows  depend  upon 
the  height  of  the  sun  above  the  horizon.  It  must 
be  close  to  the  latter,  in  order  to  enable  the  ob- 
server, standing  on  the  surface  of  the  ground,  to 
see  arcs,  or  bows,  embracing  a  half-circumference. 
It  is  only  from  the  summits  of  mountains,  or  from  a 
balloon  high  up  in  the  air,  that  complete  circles  are 
visible,  unless,  as  they  frequently  do,  they  appear  in 
the  spray  of  great  waterfalls.  A  grand  spectacle  of 
this  nature  is  enjoyed  in  contemplating  the  mag- 
nificent cascade  of  the  Reichenbach.  When  we 


WATERFALL  RAINBOWS.  p.  173. 


THE   PLAY  OF   LIGHT   IN   DROPS    OF    WATER.    173 

saw  it,  the  sun  was  rising,  and  the  brilliant  aerial 
corona,  or  crowns,  were  floating  above  the  chasm 
into  which  the  waters  plunged.  Immense  arches 
of  the  same  kind  form  upon  the  white  mist  that 
rises  over  Niagara  Falls. 

The  light  of  the  moon  also  produces  rainbows, 
but  the  yellowish  reflection  that  it  spreads  over 
all  the  colors  contrasts  unfavorably  with  the  vivid 
hues  of  the  solar  bows.  The  principal  arch  can- 
not be  seen,  and  it  is  difficult  to  distinguish  the 
variation  of  the  prismatic  rays.  During  a  storm 
which  we  witnessed  on  the  open  sea,  we  saw  a 
luminous  column  of  the  strangest  appearance  de- 
scend from  the  sky.  The  ship's  crew  were  struck 
with  terror,  and  yet  the  meteor  was  entirely  harm- 
less. The  full  moon  was  rising,  tinged  with  red, 
at  that  moment,  and  the  column  of  fire  was  but  a 
fragment  of  a  rainbow  that  it  reflected  on  a  sheet 
of  rain. 

THE   PLAY   OF   LIGHT   IN   DROPS    OF    WATER. 

All  the  appearances  of  the  phenomenon  of  the 
rainbow  show  that  it  is  produced  by  a  modification 
of  light  taking  place  in  the  drops  of  water.  These 
drops  are  spherical,  and,  during  a  shower,  follow 
each  other  so  rapidly  at  every  point,  that  we  may 
reason  concerning  them  as  though  they  remained 


174         METEORS   AND   METEORIC    PHENOMENA. 

entirely  motionless.  The  ray  that  penetrates  the 
drop  of  water  is  refracted  and  decomposed.  Instead 
of  issuing  from  it  undiminished,  as  it  went  in,  it  're- 
flects itself  partly  on  the  concave  surface  opposite 
to  the  point  where  it  entered,  and  passes  back 
through  the  globule,  until  it  again  meets  the  sur- 
face; there,  a  similar  subdivision  takes  place. 
One  portion  of  light  passes  into  the  atmosphere, 
and  the  other  is  reflected.  By  a  geometrical  dia- 
gram, it  can  be  demonstrated  that  the  drops, 
which  may  send  back  to  the  eye  of  the  observer 
rays  that  have  been  reflected  once,  or  several 
times,  are  placed  at  certain  heights,  and  form  cir- 
cular colored  bands,  each  with  a  breadth  equal  to 
the  diameter  of  the  image  of  the  sun.  The  bands 
corresponding  to  a  single  reflection  are  at  an  an- 
gular distance  of  nearly  forty  degrees  from  the 
centre.  Those  in  which  the  light  is  reflected  twice 
are  nine  degrees  farther  off.  In  each  group,  the 
differences  arising  from  dispersion  are  small 
enough  to  cause  the  bands  to  range  themselves 
one  above  the  other,  thereby  giving  rise  to  the 
series,  sometimes  regular  and  sometimes  reversed", 
of  the  colors  of  the  spectrum. 

There  is  a  simple  ^method  of  accurately  observ- 
ing the  passage  of  light  through  drops  of  water. 
Suspend  a  globe  of  thin  glass  in  a  dark  room  by 


THE  PLAY  OF  LIGHT  IN   DROPS   OF  WATEK.    1Y5 

a  cord  passing  over  a  pulley.  When  the  globe 
filled  with  water  is  so  placed  that  a  ray  of  light 
allowed  to  fall  upon  it,  through  an  orifice  in  the 
window-shutter,  forms  an  angle  of  nearly  forty- 
two  degrees  with  the  line  that  connects  it  with 
the  eye,  all  the  colors  of  the  spectrum,  commen- 
cing with  red,  can  be  seen,  one  after  the  other, 
by  merely  lowering  the  globe  gradually  from 
point  to  point.  If  the  water  be  muddy,  the  pas- 
sage of  the  ray  can  be  observed,  and  we  can  see 
that  it  undergoes  but  one  reflection.  When  the 
angle  formed  by  the  two  lines  is  fifty-four  degrees 
in  measurement,  and  the  ray  is  made  to  fall  upon 
the  lower  part  of  the  globe,  the  colors  are  ob- 
served to  form  in  like  manner,  and  in  the  same 
order,  when  the  globe  is  gradually  elevated.  The 
two  reflections  can  then  be  easily  distinguished  in 
the  water. 

According  to  the  explanation  thus  given,  the 
rainbow  is  found  to  be  purely  a  local  phenomenon. 
Each  spectator  sees  a  different  arch.  If  the  rainy 
cloud  be  near,  two  observers,  placed  at  some  dis- 
tance from  each  other,  see  the  ends  of  their  rain- 
bows resting  on  different  points  of  the  ground. 
This  fact  is  particularly  evident  when  one  is 
standing  opposite  to  a  mountain  upon  which  the 

bow  is  projected. 
9 


1T6         METEOES   AND  METEORIC   PHENOMENA. 


VARIOUS    ASPECTS    OF    THE     BOW. SUPPLEMENTARY 

ARCS. 

The  rays  of  the  sun  may  happen  to  be  re- 
flected toward  a  cloud  from  the  surface  of  a  pla- 
cid expanse  of  water,  and  this  reflection  also  may 
produce  a  rainbow.  Calculation  shows  that,  in 
such  a  case,  this  arch  must  cut  the  arch  directly 
formed,  at  a  height  that  depends  upon  the  ele- 
vation of  the  luminary.  "When  these  two  phe- 
nomena produce  a  secondary  arch,  the  four  curves, 
thus  interlaced,  offer  a  very  beautiful  sight. 
Monge  narrates  an  instance  where  they  were 
complete  in  form  and  perfectly  distinct.  Halley 
once  saw  three  afcs,  one  of  which  was  formed  by 
rays  reflected  from  the  surface  of  a  river.  The 
latter  arc  first  intersected  the  external  arc  in  such 
manner  as  to  divide  it  into  three  equal  parts. 
"When  the  sun  descended  toward  the  horizon,  the 
points  of  contact  drew  closer  together.  Ere  long 
there  was  but  one,  and,  as  the  colors  were  in  re- 
versed order  in  the  two  rainbows,  a  space  of  per- 
fect white  was  formed  at  this  sole  point  by  the 
superposition  of  the  two  series.  The  sun,  when 
high  enough  above  the  horizon,  may,  when  re- 
flected from  a  sheet  of  water,  form  a  complete 
circle.  Sometimes  the  upper  part  is  wanting, 


THE   CIRCLE   OF   TJLLOA.  177 

and  then  there  remains  the  singular  phenomenon 
of  a  rainbow  reversed. 

Supplementary  arcs  are  often  seen  when  the 
rainbow  is  very  brilliant.  "We  give  this  name  to 
colored  bands  observed  inside  of  the  interior  and 
outside  of  the  exterior  arch.  After  the  violet,  is 
usually  seen  red,  then  green,  and  then  violet 
again.  These  colors  may  even  be  repeated  sev- 
eral times  in  the  same  order.  It  is  on  the  cul- 
minating part  of  the  arch,  and  only  when  the  lat- 
ter is  very  high,  that  this  phenomenon  occurs.  It 
is  explained  by  the  laws  of  optics  that  relate  to 
refraction  ;  in  other  words,  the  modifications  that 
light  undergoes  in  grazing  the  surface  of  bodies. 

THE   CIRCLE    OF   ULLOA. 

Rainbows,  in  which  the  colors  were  extremely 
faint,  have  been  observed  in  dense  fogs.  This  ap- 
pearance arises  from  the  diminutive  size  of  the 
drops  of  moisture.  The  great  whitish  ring,  or 
circle,  seen  by  Ulloa  and  Bouguer  during  their 
gtay  on  the  Pichincha,  seems  to  have  had  this 
origin.  It  has  been  called  the  White  Rainbow,  or 
the  Circle  of  Ulloa.  Its  dimensions  are  those  of 
the  main  arch  usually  seen,  and  it  is  perceived 
only  from  elevated  places,  simultaneously  with 
the  formation  of  rainbow-like  halos  around  sLad  • 


178         METEORS    AND   METEORIC   PHENOMENA. 

ows  projected  on  the  fog.  We  have  reproduced 
the  description  of  this  phenomenon  given  by 
Bouguer,  and  will  add  what  Ulloa  says  of  it : 

"  He  was  on  Pambamarca  with  six  companions 
at  daybreak.  The  top  of  the  mountain  was  en- 
tirely covered  with  dense  clouds.  As  the  sun 
rose,  it  dispelled  these  clouds,  and  nothing  re- 
mained in  their  stead  but  some  very  light  mists, 
which  it  was  almost  impossible  to  distinguish. 
Suddenly,  on  the  side  opposite  that  in  which  the 
sun  rose,  each  of  the  travellers  saw,  at  a  dozen 
fathoms  from  where  he  stood,  an  image  of  him- 
self reflected  in  the  air,  as  though  upon  a  mirror. 
This  image  appeared  in  the  centre  of  three  rain- 
bows shaded  with  different  colors,  and  surrounded 
at  a  certain  distance  by  a  fourth  arch  of  a  single 
color.  The  tinting  farthest  on  the  outside  of  each 
arch  was  flesh-colored,  or  red,  the  next  shade  was 
orange,  the  third  was  yellow,  the  fourth  straw- 
color,  and  the  last  one  green.  All  these  arcs 
were  perpendicular  to  the  horizon;  they  moved 
about  and  followed  the  person  reflected  in  every 
direction,  surrounding  his  image  like  a  gloria. 
What  was  most  remarkable  was,  that,  although 
the  seven  travellers  stood  together  in  a  single 
group,  each  of  them  saw  the  phenomenon  only  in 
relation  to  himself,  and  was  disposed  to  deny  its 


179 

existence  in  reference  to  the  others.  The  extent 
of  these  arches  increased  progressively  in  propor- 
tion to  the  height  of  the  sun.  At  the  same  time 
their  colors  faded  away,  the  spectra  became  paler 
and  paler  and  more  vague,  and  at  last  the  phe- 
nomenon entirely  disappeared.  "When  this  dis- 
play began,  the  shape  of  the  arcs  was  oval ;  and, 
toward  the  last,  it  was  perfectly  circular. 

CROWNS,    OR   CORONA. 

When  light  clouds  pass  over  the  sun  or  the 
moon,  there  may  be  perceived  around  those  lumi- 
naries one  or  more  colored  circles,  known  to  me- 
teorology as  crowns.  In  all  these  circles,  we  dis- 
tinguish the  prismatic  colors,  the  violet  being 
placed  inside  and  the  red  outside.  They  are  at  an 
equal  distance  from  each  other,  but  this  distance 
varies  according  to  the  condition  of  the  clouds 
and  the  atmosphere.  The  angular  diameter  of 
the  first  circle  is  ordinarily  comprised  in  from  one 
to  four  degrees. 

"  All  clouds,"  says  Kaemtz,  "  that  are  not  too 
thick  to  let  the  light  of  the  sun  pass  through 
them,  the  cirrus  and  the  cirro-stratus  excepted, 
present  traces  of  crowns,  but  the  brightness  of  the 
colors  is  not  always  the  same.  I  have  never  seen 
them  so  handsome  as  upon  fogs  which  form,  dur- 


180         METEORS    AND   METEORIC   PHENOMENA. 

ing  the  night,  in  the  valleys,  and  ascend,  toward 
the  middle  of  the  day,  to  the  summits  of  the 
mountains.  When  strips  of  cloud  passed  between 
the  sun  and  me,  the  colors  had  a  vividness  which 
I  have  rarely  seen  in  them.  They  are  no  less 
fine  on  the  cirro-cumulus,  particularly  when  they 
are  in  small  masses  of  dazzling  whiteness,  and  so 
confused  on  their  edges  that  it  is  difficult  to  trace 
their  outlines  on  the  sky." 

This  phenomenon  is,  in  its  turn,  explained  by 
the  refraction  of  luminous  rays  passing  near  the 
globules  of  water  that  compose  the  clouds.  A 
very  simple  experiment  gives  us  an  imitation  of 
the  process.  We  have  only  to  hold  up  before  a 
lamp  a  strip  of  glass  besprinkled  with  lycopo- 
dium,  or  vegetable  sulphur.  The  fine  grains  of 
the  latter  substance,  acting  as  globules  do,  the 
flame  of  the  lamp  is  at  once  surrounded  by  pris- 
matic rings,  separated  by  equal  intervals. 

COLORED    HALOS. PARHELIA. 

In  the  phenomena  of  which  we  are  about  to 
treat,  small  crystallizations  of  ice,  and  not  glob- 
ules of  water,  modify  the  light.  We  are  some- 
times surrounded  by  fogs  formed  of  such  par- 
ticles. 'They  frequently  exist,  as  aeronauts  have 
ascertained,  in  the  higher  regions,  of  the  at- 


COLORED   HALOS.  181 

mosphere,  where  they  form  the  clouds  called 
cirrus. 

If  the  play  of  the  luminous  rays  in  the  little 
spheres  we  have  been  considering  has  given  us 
such  pleasing  phenomena,  we  may  readily  com- 
prehend that,  when  they  pass  through  limpid 
crystals  with  numerous  facets,  we  shall  have  fresh, 
harmonious  combinations  of  geometrical  lines  and 
of  colors  to  admire. 

In  temperate  climates,  the  phenomena  of  this 
order  most  frequently  remarked  are  the  halos,  or 
colored  circles,  that  surround  the  sun  or  the  moon, 
but  in  a  manner  different  from  crowns.  The  ar- 
rangement of  the  colors  of  the  spectrum  is  usually 
reversed  in  them,  the  red  being  placed  inside. 
The  distances  of  the  circles  from  the  luminary  are 
equable,  and  much  greater  than  in  the  corona. 
Thus,  the  interior  halo  is  from  twenty-two  to 
twenty-three  degrees  in  diameter;  the  second 
halo,  usually  called  the  external  one,  measures 
forty-six,  and  the  third  ninety-nine  degrees  in 
diameter.  Brewster  imitated  the  halo  by  placing 
a  strip  of  glass,  covered  with  crystallized  alum,  be- 
fore a  lamp.  In  order  thoroughly  to  comprehend 
the  formation  of  this  phenomenon,  we  must  sup- 
pose a  very  great  number  of  prismatic  needles  sus- 
pended in  the  air.  These  prisms,  in  certain  posi- 


182         METEOES    AND   METEORIC   PHENOMENA. 

tions,  may  revolve  for  a  considerable  period  on 
their  own  centres,  without  the  deviation  of  the 
refracted  rays  changing  perceptibly.  The  multi- 
plicity of  these  rays  proceeding  in  any  one  direc- 
tion, giving  the  eye  a  more  vivid  expression,  col- 
ored belts,  or  bands,  are  seen  placed  one  above  the 
other,  as  in  the  rainbow. 

When  the  sun  or  the  moon  is  near  the  hori- 
zon, and  the  atmosphere  remains  calm,  the  needles 
of  ice  arrange  themselves  vertically,  and  brilliant 
spots,  diffused  images  of  the  luminary,  are  formed 
along  the  horizontal  diameter  of  the  halo  and  a 
little  outside  of  each  circle.  These  take  the  name 
of  parhelia,  or  paraselene.  Parhelia,  those  of  the 
interior  halo  especially,  are  finely  colored,  all  the 
shadings  of  the  spectrum  following  the  red,  which 
is  next  to  the  sun.  "When  the  latter  luminary 
rises,  the  spots  withdraw  from  the  circles,  remain- 
ing, however,  on  the  line  of  the  horizontal  diame- 
ter. 

Sometimes  we  see,  resting  upon  the  halos, 
what  are  termed  tangential  arcs,  or  arches  of  con- 
tact, of  very  brilliant  color.  The  most  frequent 
are  those  that  form  symmetrically  at  the  extremi- 
ties of  the  vertical  diameter  of  the  halo,  of  twenty- 
three  degrees.  Those  of  the  external  halo,  which 
are  more  rare,  but  more  numerous  at  the  time, 


WHITE    ARCS.  183 

touch  it,  not  only  in  the  vertical  line  of  the  sun, 
but  also  at  the  lateral  points  forty-five  degrees 
distant.  The  most  elevated  of  these  arches,  which 
has  the  zenith  of  the  observer  for  its  pole,  is  some- 
times designated  by  the  name  of  the  circum-ze- 
nithal  circle. 

We  cannot,  here,  enter  into  details  as  to  the 
manner  in  which  these  appearances  are  produced 
by  the  refraction  of  light  in  the  crystals.  M.  Bra- 
vais,  in  his  learned  researches  on  this  subject,  did 
not  confine  himself  to  calculating  all  the  circum- 
stances of  the  phenomenon ;  he  succeeded  in  re- 
producing it  artifically,  in  a  dark  room,  by  means 
of  an  ice-prism,  which  he  caused  to  revolve  very 
rapidly  while  the  rays  of  the  sun  were  projected 
upon  it. 

WHITE   ARCS. ANTHELIA. 

The  appearances  that  we  have  now  to  describe 
are  always  entirely  white,  a  fact  indicating  that 
they  result,  not  from  the  passage  of  light  through 
the  crystals,  but  from  its  reflection  from  their 
facets.  Their  brightness  is  variable,  sometimes 
exhibiting  only  pallid  gleams  of  light,  and  some- 
times a  dazzling  splendor  like  that  of  the  central 
luminary.  First,  an  immense  circle,  called  ihepar- 
heliac  circle,  crosses  the  sun  or  the  sky,  making  the 
two  halos  intersect  each  other,  and  spanning  the 


184         METEOKS   AND   METEOKIG   PHENOMENA. 

whole  horizon  at  an  invariable  height.  Upon  this 
circle,  and  opposite  to  the  sun,  its  image  is  repro- 
duced alone,  or  accompanied  by  two  others,  which 
take  their  places  symmetrically  beside  it.  Some- 
times these  images,  or  anthelia,  are  crossed  by 
two  white  arches,  which  extend  to  a  considerable 
distance.  Vertical  columns  are  also  seen  to  form, 
in  other  words,  luminous  trains,  that  extend  twen- 
ty-five degrees  above  and  below  the  luminary, 
thus  forming,  with  a  portion  of  the  parheliac  cir- 
cle, a  cross,  with  limbs  more  or  less  unequal. 

According  to  the  savant  Babinet,  an  imitation 
of  the  parheliac  circle  is  produced  when  the  sun 
is  looked  at  through  a  crystal  of  fibrous  structure, 
cut  in  laminae  parallel  to  its  fibre,  and  placed  in 
a  vertical  position.  The  white  horizontal  belt 
which  is  then  seen  results  from  the  coruscation  of 
these  fibres.  Bravais  has  explained  this  phenom- 
enon, as  well  as  those  of  the  a/nthelia  and  their 
arcs,  by  means  of  his  ingenious  apparatus. 

Some  physiologists  attribute  to  the  effects  of 
the  mirage,  the  false  suns  and  false  moons  that 
are  sometimes  seen  beside  the  real  luminary  when 
it  is  near  the  horizon,  but  the  same  phenomena 
may  be  explained  by  the  interposition  of  an  in- 
finite number  of  small  crystals  composed  of  prisms 
and  pyramids. 


ANTHELIA.  185 

We  shall  not  enter  further  into  details  of  the 
appearances  that  halos  present.  "We  should  have 
to  add  other  curves  and  other  disks,  due  to  quite 
infrequent  crystalline  combinations,  and  we  should 
become  involved  in  too  many  complex  forms  and 
colors.  Let  us  merely  add,  that  very  brilliant 
parhelia  and  arches  themselves  become  sometimes 
sources  of  light  that  cause  similar  duplicate  phe- 
nomena, which,  however,  are  naturally  very  faint. 

In  the  illustration  given  are  seen  the  principal 
parts  of  halos.  We  must  suppose  the  white  hori- 
zontal belt  to  be  prolonged  to  the  side  of  the 
heavens  opposite  the  sun,  where  the  image  of 
that  luminary  is  repeated  several  times.  But  the 
phenomenon  scarcely  ever  has  its  complete  devel- 
opment. Sometimes  it  is  one  and  sometimes  an- 
other form  of  crystals  that  is  produced  in  the  at- 
mosphere, and  these  diminutive  bodies  float  there, 
or  descend  slowly,  in  different  positions,  accord- 
ingly as  the  air  is  calm  or  agitated.  The  parts 
that  we  have  represented  are,  consequently,  seen 
together  but  seldom,  and  it  is  not  surprising, 
therefore,  to  find  a  great  variety  of  different 
accounts  by  different  observers. 

It  is  generally  noticed  that  the  sky,  on  the 
inside  of  the  halo  of  twenty-three  degrees,  is  in 
striking  contrast,  by  its  dark-gray  color,  with  the 


186          METEOKS   AND   METEOEIC   PHENOMENA. 

general  illumination  of  the  external  space.  This 
peculiarity  is  explained  by  the  direction  of  certain 
rays,  refracted  by  the  prisms  which  produce  the 
halo.  As  in  rainbows,  there  is  a  great  difference  in 
brightness  between  the  solar  and  the  lunar  halos. 
In  the  latter,  the  colors  are  always  very  dull,  but 
the  white  parts  of  the  great  geometrical  figure, 
when  it  is  formed,  always  throw  back  a  beautiful 
silvery  light. 

THE   HALO   OF   CLEKE. 

A  remarkable  display  of  halos  and  paraselenes 
was  observed  on  February  21,  1864,  at  eight 
o'clock  in  the  evening,  in  many  localities  of  the 
Departments  of  Indre-et-Loire  and  Loire-et-Cher, 
in  France. 

"  It  was  at  Clere  that  the  phenomenon  pre- 
sented the  most  curious  appearance. 

"  The  sky  was  clear  and  cloudless,  and  even  the 
stars  could  be  seen,  notwithstanding  the  moon- 

light. 

"  All  at  once,  rays  of  a  silvery  white,  darting 
apparently  from  the  moon,  described  a  Greek 
cross,  of  which  the  moon  occupied  the  centre.  A 
white  ring  of  a  deeper  tinge  connected  the  arms 
of  the  cross,  and  thus  formed  a  first  and  magnifi- 
cent lunar  halo. 


THE    HALO    OF   CLERE.  187 

"At  each  arm,  one  extending  to  the  north 
and  the  other  to  the  south,  and  at  equal  distances 
from  them,  the  image  of  the  moon  was  reproduced 
by  a  luminous  globe  of  the  same  size,  half  white, 
and  half  tinged  with  the  colors  of  the  rainbow. 
These  globes  sometimes  darted  out  luminous  rain- 
bow-colored rays,  like  the  tail  of  a  comet. 

"  A  second  halo,  in  an  immense  circle  outside 
of  the  first  one,  and  starting  from  the  luminous 
globes  that  tipped  the  arms  of  the  cross,  surround- 
ed the  borough  of  Clere.  It  was  of  exactly  the 
same  color  as  the  first  one.  This  second  halo  also 
displayed  two  luminous  globes,  in  all  respects 
similar  to  the  first  pair,  at  an  equal  distance  on 
its  circumference.  Thus,  there  were  five  lumi- 
nous globes,  including  the  moon,  all  connected  by 
the  rings  and  the  branches  of  the  cross. 

"  What  was  still  more  curious  was,  that  two 
crescents  of  unequal  size,  and  placed  at  a  certain 
distance  one  above  the  other,  occupied  the  centre 
of  the  second  halo  above  the  cross,  without  any 
direct  association  with  the  rest  of  the  phenome- 
non." 

At  Mettray,  the  appearance  was  as  follows : 
"  The  silvery  circle  around  the  moon  was  cut 
by  two  perpendicular  luminous  diameters.  One 
of  these,  running  northeast  and  southwest,  exhib- 


188         METEORS   AND  METEORIC   PHENOMENA. 

ited  at  each  extremity  the  hues  of  the  rainbow. 
These  two  points,  thus  rich  in  coloring,  projected 
of  themselves,  beyond  the  circle,  a  long,  luminous, 
but  colorless  train,  affecting  the  form  of  part  of 
an  ellipse. 

"  The  phenomenon  passed  through  different 
phases,  in  consequence  of  the  displacement  of  the 
clouds,  or  more  probably  of  the  snowy  mass  in- 
terposed between  the  moon  and  the  eye  of  the 
spectator. 

"  The  luminous  diameters  disappeared  slowly, 
and  the  circle  became  gradually  depressed,  so  as  to 
assume  a  completely  elliptical  form.  The  curve 
at  the  same  time  became  tinted  with  the  colors  of 
the  rainbow,  but  dimmer  than  they,  while  the  two 
extremities  of  the  long  diameter,  which  had  been 
prismatically  variegated  since  the  first  appearance 
of  the  halo,  continued  to  show  great  luminous  in- 
tensity." 

To  conclude :  at  Amboise,  the  phenomenon 
presented  features  no  less  remarkable : 

"  In  fine,  clear  weather,  that  left  the  stars  plain- 
ly distinguishable,  the  full  moon  however  being 
slightly  clouded,  there  gradually  appeared  a  halo, 
or  luminous  circle,  of  considerable  dimensions, 
with  the  moon  in  the  centre.  At  the  same  time, 
another  circle  formed,  no  less  in  breadth  than  the 


THE   HALO   OF   CLERE.  189 

first  one,  but  much  greater  in  upward  length,  and 
the  moon  occupied  a  point  in  its  circumference, 
to  the  southward.  The  two  circles  intersected 
each  other,  and  the  refracted  light  being  in  some 
sort  accumulated  at  the  two  points  of  intersection, 
situated  to  the  eastward  and  westward  of  the 
moon,  two  luminous  foci  were  seen  there,  which 
gradually  displayed  all  the  colors  of  the  rainbow, 
perfectly  visible  and  perfectly  distinct." 


CHAPTER   VIII. 

THE  AURORAL  LIGHTS. 


General  Description.— Icy  Fog.— Noise  and  Odor.— Electrical  Currents. 
—Magnetic  Influence.— The  Aurora  Australia.— Different  Points  of 
View.— Periodicity  of  the  Auroral  Lights. 


GENERAL   DESCRIPTION. 

MANY  hours,  and  sometimes  a  whole  day,  be- 
fore the  appearance  of  the  aurora  borealis,  irregu- 
lar movements  are  observed  in  the  magnetic  nee- 
dle. During  that  time  its  deviation  to  the  west, 
or  declination,  sensibly  augments.  Little  by  lit- 
tle, toward  the  north,  the  atmosphere  thickens 
along  the  horizon,  and  a  curtain  of  violet  mists, 
thin  enough  to  let  the  stars  be  seen  through  them, 
begins  to  ascend.  Its  upper  border  brightens 
feebly  at  first,  and  then  this  illumination  becomes 
more  and  more  regular,  and  forms  an  arch  of  a 
pale-yellow  hue,  turning  its  concavity  toward  the 
earth,  and  with  its  summit  in  the  meridian. 

This  arch  ascends  slowly,  and  gradually  be- 


GENERAL   DESCRIPTION.  191 

comes  more  luminous.  Striated  rays  of  blackish 
tint  assume  shape,  and  a  sort  of  effervescence  is 
observed  along  the  entire  extent  of  the  arch.  Ere 
long,  other  rays  shoot  up  of  various  length  and 
brightness,  and  dart  into  the  sky,  like  rockets. 
The  fiery  train,  which  at  times  is  dazzling,  passes 
from  purply-red  to  emerald-green,  but  most  usu- 
ally a  magnificent  yellow  tinge  predominates. 

In  their  upward  flight,  these  rays  go  beyond 
the  zenith,  and  seem  to  converge  toward  the  same 
point  in  the  sky,  namely,  the  magnetic  zenith,  in- 
dicated by  the  prolongation  of  a  magnetic  needle 
freely  suspended. 

In  order  to  depict  the  suddenness  of  the  varia- 
tions of  light  in  the  rays,  Bravais,  like  ourselves, 
says  that  they  dart.  Occasionally,  they  are  so 
multiplied  that  they  invade  the  entire  celestial 
vault,  forming  an  immense  cupola  of  fire,  agitated 
like  the  billows  of  the  sea.  ~No  description  could 
do  justice  to  the  splendor  of  this  spectacle. 

With  the  first  streaks  of  the  aurora,  the  mag- 
netic needle  is  subjected  to  lively  oscillations. 
These  augment  when  the  rays  appear.  Each  one 
of  them,  as  it  shoots  from  the  arch,  makes  the  com- 
pass, in  some  sort,  palpitate,  and  then  sailors  say 
that  it  is  bewitched.  Intervals  of  tranquillity,  that 
grow  more  and  more  frequent,  next  mark  the  de- 


192         METEOKS   AND   METEORIC   PHENOMENA. 

clining  phase  of  the  aurora,  and  it  has  been  as- 
certained that  the  deviation  of  the  needle  then 
takes  place  in  the  inverse  ratio  of  its  declination 
when  the  phenomenon  began. 

M.  Lottin,  intrusted,  in  common  with  M.  Bra- 
vais,  with  a  scientific  mission  to  Iceland,  describes 
a  remarkable  undulating  motion  that  may  be 
noticed  in  the  auroral  beams  when  watched  atten- 
tively. 

"  While  the  arch,"  says  he  "  is  ascending  tow- 
ard the  zenith,  with  every  additional  foot,  the 
brightness  of  each  beam  successively  gathers  in- 
tensity. This  kind  of  luminous  current  displays 
itself  several  times  in  succession,  and  much  more 
frequently  from  west  to  east  than  in  the  opposite 
quarter.  Sometimes,  but  rarely,  a  retrograde 
movement  takes  place  immediately  after  the  first 
one,  and  as  soon  as  the  glow  has  run  through  all 
the  beams,  one  after  the  other,  from  west  to  east, 
it  changes  to  the  opposite  direction,  thereby  re- 
turning to  its  point  of  departure,  without  our 
being  able  to  say  whether  it  is  the  rays  that  are 
thus  carried  across  by  a  nearly  horizontal  move- 
ment, or  this  brighter  light  speeding  from  one 
beam  to  the  other,  step  by  step,  without  the  latter 
undergoing  any  displacement." 

We  shall  see,  further  on,  that  this  appearance 


GENERAL   DESCRIPTION.  193 

arises,  in  reality,  from  a  transfer  of  the  beams 
themselves. 

Sometimes,  when  the  ends  of  the  auroral  arch 
have  left  the  horizon,  and  it  is  rising  higher  in  the 
sky,  the  alternate  motion  of  the  rays  attached  to 
it  make  it  look  like  a  long,  golden  drapery  float- 
ing in  the  atmosphere,  folding  and  reopening  in  a 
thousand  ways,  and  undulating  as  though  agitated 
by  the  wind.  This  first  arch  fades  and  dies  out 
by  degrees  as  it  ascends,  but,  in  the  mean  time, 
new  ones  present  themselves,  some  of  them  com- 
mencing diffusely,  and  others  with  beams  already 
formed.  Nine  arches  have  been  counted  at  one 
time,  forming  in  this  manner,  and  passing  through 
nearly  the  same  phases. 

In  the  region  toward  which  the  beams  con- 
verge, there  often  appears  a  luminous,  elliptical 
curve,  called  the  boreal  corona,  or  crown.  It 
seems  to  be  merely  an  effect  of  perspective.  The 
rays,  running  parallel  to  the  magnetic  needle 
freely  suspended,  are  disposed  like  the  ridges  of 
a  cylindrical  tunnel,  which  are  seen  converging 
toward  the  centre  of  the  two  openings.  When 
this  corona  appears,  the  aurora  is  in  its  complete 
development.  It  does  not  remain  long  visible, 
however,  and  the  phenomenon  soon  enters  upon 

its   declining  phase.     The  beams   become  more 
10 


194         METEORS   AND   METEORIC   PHENOMENA. 

sparse,  shorter,  and  less  vividly  colored.  "  Bundles 
of  rajs,"  says  M.  Lottin,  "  belts,  and  fragments 
of  arcs,  appear  and  disappear  at  intervals.  Then 
the  beams  become  more  and  more  diffused,  until 
they  are  seen  only  as  vague  and  feeble  gleams, 
which,  at  last,  spread  over  the  whole  firmament, 
grouped  together  like  small  cumuli,  and  designated 
by  the  name  of  auroral  flakes.  Their  milky-white 
radiance  often  undergoes  very  vivid  changes  of 
intensity,  similar  to  dilating  and  contracting 
movements,  which  are  propagated  from  the  centre 
to  the  circumference,  and  recall  those  of  the  marine 
animals  known  as  medusce.  The  twilight  phase 
comes  on,  little  by  little,  and  the  phenomenon, 
gradually  fading  away,  at  length  ceases  to  be 
visible.  At  other  times,  the  rays  still  appear  at 
daybreak,  and  then  suddenly  vanish;  or,  as  the 
morning  twilight  grows  brighter,  they  become 
more  vague,  assume  a  whitish  color,  and  end  by 
commingling  and  losing  themselves  in  the  cirro- 
stratus,  in  such  manner  that  it  is  impossible  to 
distinguish  them  from  that  species  of  cloud." 

ICE-FOGS. 

Our  remarks,  just  made  in  reference  to  the  last 
phase  of  auroras,  indicate  their  relations  with  the 
clouds  composed  of  small  crystals  of  ice.  It  is 


ICE-FOGS.  195 

very  easy  to  make  out,  by  daylight,  those  foggy 
points  in  the  sky  which  were  seen  in  the  form  of 
auroral  flakes,  while  they  were  illuminated  by 
electricity,  which  is  the  first  cause  of  the  phenom- 
enon. Sometimes,  also,  trains  of  cirrus  are  per- 
ceived in  the  region  where  the  most  brilliant 
beams  were  seen.  Admiral  Wrangel  remarked 
that  halo  arches  formed  around  the  moon  at  the 
moment  when  auroral  rays  darted  in  the  direc- 
tion of  that  luminary. 

"  During  the  daytime,"  said  Humboldt, 
"clouds  sometimes  group  together,  and  arrange 
themselves  almost  like  the  rays  of  an  aurora  bore- 
alis,  and  then  they  seem  to  disturb  the  magnetic 
needle."  Father  Secchi,  the  director  of  the  ob- 
servatory at  Rome,  has  also  established  the  fact 
that  magnetic  perturbations  manifest  themselves 
at  night  when  light  phosphorescent  clouds  veil 
the  heavens.  These  are,  in  a  certain  degree, 
feeble  our  or  OB.  Every  body  has  had  a  chance  to 
notice  the  Polar  belts  described  by  Humboldt. 
These  clouds  are  disposed  in  long  parallel  lines  in 
the  direction  of  the  magnetic  meridian,  and  are 
seen  quite  frequently  in  our  climates.  M.  de 
Tessan,  in  his  account  of  the  voyage  of  the  Yenus, 
reports  that  one  of  the  officers  of  the  frigate  al- 
ways predicted  fine  auroras  from  having  observed 


196         METEORS   AND   METEORIC   PHENOMENA. 

the  arrangement  of  the  cirrus  during  certain 
days. 

In  Canada,  meteorological  registers  have  been 
kept,  for  a  long  time,  which  indicate  the  state  of 
the  atmosphere  on  days  that  precede  and  follow 
auroral  displays.  On  nearly  all  those  days  there 
has  been  either  snow  or  rain,  a  circumstance  which 
renders  it  very  probable  that  icy  particles  were  in 
the  atmosphere  during  the  presence  of  the  aurora. 
This  infinite  quantity  of  extremely  delicate  crys- 
tals, traversed  by  electric  currents,  constitutes,  as 
it  were,  an  immense  luminous  net- work  floating  in 
the  atmosphere. 

It  must  be  borne  in  mind  that  all  these  delicate 
needles  of  ice  may  exist  in  the  air  while  the  sky 
continues  to  look  perfectly  serene.  Doctor  Rich- 
ardson, in  fine  weather,  and  at  a  temperature  of 
thirty-two  degrees  (centigrade)  below  zero,  saw 
the  arc  of  the  aurora  in  the  neighborhood  of  the 
zenith,  and,  at  the  same  moment,  remarked  the 
fall  of  an  extremely  fine  snow,  which  was  scarcely 
visible,  but  which  left  drops  on  his  hand  in  melt- 
ing. 

The  existence  of  the  fog  that  is  seen  on  the 
horizon,  in  the  form  of  a  darkish  segment,  before 
the  commencement  of  this  luminous  phenomenon, 
confirms  the  preceding  observations.  In  north- 


NOISE   AND   ODOE.  197 

era.  countries,  travellers  have  found  themselves,' 
when  on  the  summits  of  mountains,  suddenly  en- 
veloped in  a  transparent  mist  of  a  grayish  color, 
bordering  on  green,  which  then  became  trans- 
formed, in  a  higher  region,  to  a  splendid  aurora 
borealis. 

NOISE   AND   ODOR. ELECTEIC   CUEEENTS. 

When  the  point  of  observation  is  sufficiently 
near  the  aurora,  there  is  heard  a  peculiar  rustling 
sound,  mixed  with  sudden  crackling  noises,  analo- 
gous to  those  produced  by  electricity  when  it 
escapes  from  a  body  in  the  form  of  an  aigrette  or 
a  sheaf.  Frequently  a  sulphurous  smell  is  in  the 
air,  and  this  is  due,  no  doubt,  to  the  ozone  which 
is  produced  during  the  electric  discharges  of  the 
pole,  as  it  is  in  a  thunder-storm. 

When  treating  of  storms,  we  said  that  the 
atmosphere  is  constantly  charged  with  positive 
electricity,  produced  in  great  part  in  the  tropical 
regions.  The  earth,  on  the  contrary,  is  negative- 
ly electrified,  and  a  neutralization  is  effected  by 
means  of  the  humidity  of  the  lower  strata  of  the 
atmosphere.  Says  De  la  Rive,  to  whom  we  are 
indebted  for  this  theory  :  "  It  is  principally  in  the 
polar  regions,  where  the  eternal  ices  condense  the 
aqueous  vapors  incessantly  in  the  form  of  fog,  that 


198         METEORS   AND   METEORIC   PHENOMENA. 

this  neutralization  should  take  place ;  and,  with 
the  greater  reason,  that  the  positive  vapors  are 
borne  thither  and  accumulated  by  the  tropical 
current,  which,  starting  from  the  equatorial  re- 
gions, where  it  occupies  the  highest  range  of  the 
atmosphere,  descends  as  it  advances  toward  the 
more  elevated  latitudes,  until,  in  the  vicinity  of 
the  poles,  it  comes  in  contact  with  the  earth.  It 
is  there,  then,  that  the  discharge  of  the  positive 
electricity  of  the  mists,  and  the  negative  electri- 
city of  the  earth,  should  essentially  take  place, 
with  an  accompaniment  of  light,  when  it  is  in- 
tense enough,  if,  as  is  almost  always  the  case  near 
the  poles,  and  sometimes  in  the  upper  parts  of 
the  atmosphere,  it  encounters  in  its  course  parti- 
cles of  ice  of  extreme  tenuity  which  form  the  fogs 
and  clouds  very  high  up  in  the  air." 

According  to  the  more  or  less  foggy  condition 
of  the  atmosphere  in  the  polar  regions,  and  there- 
fore its  greater  or  inferior  capacity  as  a  con- 
ductor, the  two  electricities  more  or  less  readily 
neutralize  each  other.  Hence  arise  currents  of 
variable  intensity  that  traverse  the  surface  of  the 
earth  from  the  pole  to  the  equator.  It  is  the  in- 
fluence of  these  currents  upon  the  magnetic  needle 
which  produces  the  deviations  and  oscillations 
that  we  have  signalized. 


ELECTRIC   CURRENTS.  199 

These  perturbations  are  continual  in  the  high- 
est latitudes,  because  the  intensity  of  the  elec- 
tric currents  is  greater,  and  their  influence  more 
marked.  In  proportion  as  we  descend  toward 
the  equator,  we  notice  fewer  deviations,  but  still 
they  take  place  to  some  extent  everywhere,  even 
in  places  where  the  aurora  is  not  visible.  For 
several  years  Arago,  in  following  the  variations 
of  the  needle  at  the  observatory  of  Paris,  was  able 
to  announce  the  appearance  of  the  aurora  borea- 
lis  in  the  Eastern  Hemisphere,  without  being  once 
mistaken. 

During  the  fine  aurora  of  November  27,  1848, 
Signor  Mateucci  observed  the  influence  of  the 
currents  in  a  very  remarkable  form.  He  writes : 
"I  was  at  the  electric-telegraph  office  in  Pisa, 
when  we  were  suddenly  surprised  by  the  appa- 
ratus ceasing  to  work,  although  it  had  always 
operated  perfectly  well  in  the  daytime.  The 
same  thing  happened  at  the  same  moment  in 
Florence.  We  tried  to  make  it  go  by  increasing 
the  force  of  the  currents,  and  then  by  acting 
upon  the  manipulators ;  but  all  in  vain, — the 
anchor  remained  attached  to  the  electro-magnets." 
This  singular  effect  ceased  when  the  aurora  dis- 
appeared, and  the  apparatus  again  performed  its 
task  as  perfectly  as  ever.  In  England,  Mr.  High- 


200         METEOES   AND   METEORIC    PHENOMENA. 

ton  has  recorded  the  very  prolonged  effect  of  the 
aurora  upon  the  telegraph-wires. 

In  all  parts  of  the  European  net- work  of  tel- 
egraphs the  working  of  the  wires  was  disturbed 
by  the  magnificent  aurora  of  August  28,  1859. 
Two  days  later,  the  luminous  phenomenon  was 
perceived  over  a  great  part  of  the  continents  of 
Europe,  Asia,  and  America,  and  a  magnetic  action 
still  more  general  was  noticed.  There  were  cur- 
rents sufficiently  intense  to  cause  a  spark  to  be 
thrown  off  when  they  were  interrupted.  In  the 
United  States,  two  telegraph-operators,  stationed 
at  Boston  and  Portland,  were  able  to  use  the  terres- 
trial fluid,  which  was  much  more  powerful  than 
that  of  the  machine,  and  kept  up  a  conversation 
for  some  time. 

MAGNETIC   INFLUENCE. 

Let  us  now  consider  the  great  mass  of  lumi- 
nous fog  placed  in  the  icy  zone,  and  acting  as  a 
species  of  movable  conductor  traversed  by  a  suc- 
cession of  electrical  discharges.  The  globe  being 
considered  a  huge  magnet,  what  is  the  action  of 
the  magnetic  pole  upon  this  fog  ? 

To  M.  de  la  Rive  we  are  indebted  for  a  very 
interesting  experiment  in  physics,  which  has  put 
us  in  a  way  to  solve  this  problem.  He  took  a 


MAGNETIC   INFLUENCE.  201 

hollow  ball  of  glass,  in  which  the  air  was  extreme- 
ly rarefied,  and  arranged  inside  of  it  an  apparatus 
causing  jets  of  electric  light  to  converge  upon  the 
pole  of  an  electro-magnet.  He  states  the  result 
as  follows  :  "  As  soon  as  the  cylinder  of  soft  iron, 
which  serves  for  an  electro-magnet,  is  magnetized, 
the  electric  light,  instead  of  starting  indifferently 
from  different  points  of  the  upper  surface,  which 
serves  as  a  pole,  as  it  did  before  being  magnetized, 
parts  from  all  the  points  of  the  circumference  of 
that  surface,  in  such  manner  as  to  form  a  sort  of 
continuous  luminous  ring  around  it.  That  ring 
has  a  kind  of  rotary  movement  around  the  mag- 
netized cylinder,  sometimes  in  one  direction  and 
sometimes  in  another,  according  to  the  direction 
of  the  discharge,  and  the  sense  in  which  the  mag- 
netizing was  done.  Finally,  some  jets  of  light 
more  brilliant  than  the  rest  seem  to  shoot  forth 
from  this  luminous  circumference,  without  becom- 
ing confounded  with  the  rest  of  the  sheaf  of  rays. 
As  soon  as  the  magnetic  state  ceases,  the  luminous 
phenomenon  becomes  what  it  was  before." 

Relying  upon  this  experiment,  M.  de  la  Rive 
constructed  an  apparatus  consisting  of  a  wooden 
sphere,  with  a  covering  of  soft  iron,  to  represent 
the  earth.  With  this  apparatus  he  was  able  to  re- 
produce not  only  the  polar  aurorae  but  also  the 


202         METEORS   AND   METEOEIC   PHENOMENA. 

different  effects  that  they  determine,  such  as  the 
disturbance  of  the  magnetic  needle  and  the  move- 
ments of  electricity  in  the  telegraphic  wires. 

We  have  said  that  the  arc  of  the  aurora  ^ore- 
alls  always  has  its  summit  placed  in  the  mag- 
netic meridian.  In  the  great  aurora  of  the  au- 
tumn of  1859,  the  arc  appeared  to  have  its  centre 
toward  the  northwest  in  California,  nearly  at  the 
north  in  Philadelphia,  and  toward  the  northwest 
in  England.  This  would  place  the  real  centre  in 
North  America.  A  great  number  of  like  observa- 
tions have  led  to  the  same  result,  and  the  aurorae 
thus  present  themselves  to  us  as  luminous  rings 
of  variable  diameter,  centred  around  the  magnet- 
ic pole,  and  hovering  at  a  greater  or  less  height 
in  the  atmosphere,  shooting  forth  vertical  rays. 
The  undulating  movement  of  the  arch,  and  of  the 
radiations  emanating  from  it,  described  by  M. 
Lottin,  which  would  seem  to  indicate  their  rota- 
tion from  the  west  to  the  east,  passing  up  by  the 
south,  adds  another  feature  of  resemblance  be- 
tween the  great  phenomenon  and  the  experiment 
of  M.  de  la  Eive.  In  fact,  it  is  in  this  sense 
that  the  ring  should  turn  when  the  positive  elec- 
tricity issuing  from  the  atmosphere  is  directed 
toward  the  north  magnetic  pole. 

The  form  and  movements  of  the  aurora  are 


THE  AURORA   AUSTRALIS.  203 

therefore  determined  by  the  forces  which  emanate 
from  the  grand  terrestrial  magnet.  And  we  may 
add  a  remarkable  observation  of  M.  Hansteen: 
"  During  the  aurora,  and  for  several  days  after- 
ward, the  magnetic  intensity  is  notably  dimin- 
ished, and  recovers  its  usual  value  only  by  de- 
grees." 

THE   AURORA   AUSTKALIS. 

Judging  from  such  few  observations  as  have 
been  collected  in  the  southern  hemisphere,  it 
may  be  said  that  the  aurora  australis,  or  southern 
aurora,  presents  the  same  phenomena  as  the  au- 
rora borealis.  It  is  explained  in  a  similar  manner. 
Several  cases  of  coincidence  between  the  illumina- 
tions of  the  two  poles  have  been  remarked. 

M.  de  Tessan  has  given  the  following  descrip- 
tion of  a  southern  aurora,  observed  during  the 
voyage  of  the  Yenus  :  "  On  January  20,  1839,  at 
twenty  minutes  past  one  o'clock  in  the  morning, 
we  noticed  a  fine  aurora  forming  a  very  apparent 
and  clearly-marked  luminous  arc  of  a  circle.  Its 
radiance  was  white;  there  may,  however,  have 
been  a  slight  greenish  tinge,  for  it  reminded  one 
somewhat  of  the  light  of  a  phosphorescent  body. 
This  light  was  soft  and  steady,  and  might  be  com- 
pared, as  to  brightness,  with  that  of  the  upper 


204:         METEORS   AND   METEORIC   PHENOMENA. 

edge  of  a  cloud  of  the  cumulus  order  from  behind 
which  the  moon  is  just  emerging.  Flashes,  or 
beams,  equally  white,  but  of  much  less  intensity, 
rose  from  different  points  of  the  arc.  These 
flashes  appeared  and  disappeared,  very  perceptibly, 
in  the  same  place,  after  a  variable  duration  of 
from  five  to  ten  minutes. 

"  The  lower  part  of  the  arc  seemed  to  be  occu- 
pied by  a  large  black  cloud,  the  borders  of  which, 
adjacent  to  the  arc,  were  slightly  notched.  I  took 
this  appearance  for  a  real  cloud ;  I  noted  it  as 
such,  and  not  a  doubt  on  the  subject  would  have 
entered  my  mind,  had  I  not,  since  my  return,  seen 
similar  appearances  cited  as  deceptive  by  skilful 
observers,  who  assure  us  that  they  could  see  the 
stars  through  this  apparently  dense  cloud. 

"  The  sky  was  quite  clear,  and  only  dotted 
with  a  few  large  clouds,  while  the  stars  were  very 
brilliant.  We  heard  no  particular  noise  from  the 
direction  of  the  aurora." 

DIFFERENT  POINTS   OF   VIEW. THE   PERIODICITY   OF 

AURORAS. 

Frequently,  observers  at  the  north  have  found 
themselves  placed  in  the  middle  of  the  aurora, 
below  the  luminous  ring.  At  that  time  the  arch  ex- 
tended beyond  the  zenith,  and  in  a  great  measure 


DIFFERENT   POINTS    OF   VIEW.  205 

concealed  the  trajectory  of  the  rays.  It  is  in  these 
conditions  that  the  noise  of  the  electric  discharges 
becomes  perceptible,  as  well  as  the  smell  of  ozone. 
The  curious  circumstance  has  been  remarked,  that 
the  magnetic  needle  remains  completely  motion- 
less there,  while  it  is  keenly  agitated  everywhere 
else  on  the  surface  of  the  globe.  The  direction 
assigned  by  theory  to  the  currents  accounts  for 
this  effect. 

In  our  middle  latitudes,  the  aurora  borealis 
usually  displays  itself  in  a  coloring  of  the  sky, 
which  looks  like  the  reflection  of  a  conflagration. 
We  likewise,  but  less  often,  see  large,  reddish 
clouds,  from  which  sometimes  shoot  forth  beams 
that  ascend  to  the  zenith.  Before  this  meteor  was 
completely  understood,  and  admired  for  its  beauty, 
and  for  the  solace  afforded  by  its  brilliant  illumi- 
nation during  the  long  polar  nights,  it  was  in 
Europe  a  source  of  terror.  In  antiquity  and  the 
middle  ages,  those  red  flames,  those  shooting 
rays,  seemed  blazing  torches,  and  swords  dipped  in 
blood.  The  imagination  at  one  time  depicted  an 
immense  conflict,  in  which  men  of  fire  struggled 
for  mastery;  and,  at  another,  an  assemblage  of 
hideous  heads  tossing  their  flaming  tresses. 

The  aurora  borealis  is  not  always  visible.  It 
is,  very  probably,  a  phenomenon  that  frequently 


206         METEORS   AND   METEORIC    PHENOMENA. 

occurs  in  the  daytime.  During  a  winter  passed 
at  Bossecop,  in  the  seventieth  degree  of  latitude, 
M.  Lottin  counted  one  hundred  and  fifty  auroras 
in  two  hundred  nights.  Naturally,  the  number 
of  appearances  of  the  phenomenon  grows  smaller 
as  we  recede  more  and  more  from  the  magnetic 
pole. 

An  annual  periodicity  has  been  remarked  in 
the  visible  auroras,  the  number  of  which  increases 
as  we  approach  the  equinoxes,  and  diminishes  at 
the  epoch  of  the  solstices.  These  fluctuations  must 
depend  upon  the  greater  or  less  abundance  of  va- 
pors carried  toward  the  poles  during  different 
seasons.  At  the  equinoxes,  circumstances  are 
perceptibly  the  same  in  the  two  hemispheres,  and 
it  is  also  at  this  epoch  that  the  simultaneousness 
of  the  boreal  and  austral  auroras  has  been  noted. 


CHAPTER  IX. 

SHOOTING-STARS. 


Fire-balls.— Showers  of  Stones.— Meteoric  Stones.— An  Extraordinary 
Meteor.— Velocity  and  Appearance  of  Fire-balls.— The  Fall  of  Aero- 
lites.—Periodical  Reappearances.— Composition  of  Aerolites.— Dark- 
ening of  the  Sun.— Ring  of  Meteorites. 


FIRE-BALLS. 

EVERY  one  has  seen  the  luminous  furrows  of 
various  colors,  direction,  and  extent,  which  are 
rapidly  traced  across  the  constellations,  sometimes 
by  brilliant  luminous  points  without  apparent 
diameter,  and  sometimes  by  globes  of  fire  of  divers 
dimensions.  The  latter,  which  are  spoken  of  as 
fire-balls,  or  bolides,  sometimes  split  into  pieces  at 
the  end  of  their  course,  with  a  loud  report,  and 
leaving  a  small  cloud  at  the  point  where  they  dis- 
appeared. 

Dazzling  trains  of  light  and  blazing  bolides 
have  been  seen  in  broad  daylight,  but  very  rarely. 
During  the  night  an  average  of  ten  shooting-stars 


208         METEORS   AND   METEORIC   PHENOMENA. 

per  hour  is  seen,  but,  in  certain  seasons  of  the 
year,  they  cross  the  heavens  in  swarms,  and  nu- 
merous fire-balls  are  sometimes  interspersed  with 
these  great  displays. 

Divers  causes  have  been  assigned  for  these 
phenomena.  Kepler  believed  them  to  be  engen- 
dered by  "  terrestrial  exhalations,"  and  this  opin- 
ion has  been  handed  down  to  our  day,  with  but 
little  modification.  Most  savants,  however,  have 
adopted  another  way  of  accounting  for  them. 
They  attribute  all  these  meteors  to  mineral  mass- 
es known  by  the  name  of  aerolites,  which,  when 
they  fall  to  the  ground,  exhibit  traces  of  intense 
combustion.  A  passage  in  Plutarch  shows  that 
the  ancients  had  adopted  that  explanation: — 
"  Some  philosophers,"  he  says,  in  his  life  of  Ly- 
sander,  "think  that  shooting-stars  do  not  arise 
from  detached  parts  of  ether  coming  to  extinguish 
themselves  in  the  air,  immediately  after  taking 
fire ;  nor  do  they  spring  from  the  atmosphere  in 
a  state  of  dissolution,  in  great  quantity,  in  the  up- 
per regions ;  they  are  rather  heavenly  bodies  that 
fall  to  the  earth,  or,  in  other  words,  bodies  with- 
drawn in  some  manner  from  the  force  of  rotation, 
and  precipitated,  not  only  upon  the  inhabited 
regions,  but  upon  the  great  seas,  whence  it  comes 
that  they  are  not  afterward  found." 


SHOWERS   OF  STONES.  '          209 

Diogenes  of  Apollonius  mentions  a  star  of 
stone  that  fell  "  all  on  fire  near  ^Egos  Potamos." 
The  fall  of  this  aerolite  made  a  great  impression 
on  the  inhabitants  of  Thrace.  According  to  the 
description  that  has  remained  to  us,  it  was  twice 
the  size  of  an  ordinary  millstone,  and  made  a 
whole  wagon-load  by  itself.  A  shower  of  stones 
fell  near  Eome  during  the  reign  of  Tullus  Hostilius. 
In  Galatia,  Cybele  was  worshipped  in  the  form  of 
a  stone  that  had  fallen  from  the  sky.  At  Emesis, 
in  Syria,  a  similar  stone  was  set  apart  for  the 
worship  of  the  sun.  These  two  meteoric  stones 
were  subsequently  transported  to  Home. 

SHOWERS   OF   STONES. 

Even  as  late  as  the  eighteenth  century,  learned 
men  did  not  believe  in  stones  falling  from  the  sky. 
It  was  only  in  1Y94  that  Chladni  attempted  to  de- 
monstrate the  truth  of  the  explanation  which  had 
been  stowed  away  among  popular  superstitions. 
Not  long  afterward,  in  1803,  on  the  26th  of 
April,  a  shower  of  stones  fell  upon  the  small  town 
of  Laigle,  in  Normandy,  and  dispelled  all  doubt 
on  the  subject.  A  regular  statement  was  drawn 
up,  and  the  messenger  of  the  Institute  who  went 
to  the  spot  made  a  report,  which  Humboldt  has 
quoted  in  his  "  Cosmos,"  as  follows : 


210         METEORS  AND   METEORIC   PHENOMENA. 

"  At  one  o'clock  in  the  afternoon,  with  the  sky 
perfectly  clear,  a  large  fire-ball  was  seen  from 
Alencon,  Falaise,  and  Caen,  moving  through  the 
air  from  southeast  to  northwest.  Shortly  after- 
ward there  was  heard  at  Laigle,  for  four  or  five 
minutes,  an  explosion  coming  from  a  small  and 
almost  motionless  black  cloud.  This  was  followed 
by  three  or  four  others,  and  a  noise  that  one 
would  imagine  was  produced  by  discharges  of 
musketry  mingled  with  the  rolling  of  a  great 
number  of  drums.  Each  explosion  detached  from 
the  black  cloud  some  of  the  vapors  that  formed 
it.  At  that  point  no  luminous  phenomenon  was 
observed.  More  than  two  thousand  meteoric 
stones,  of  which  the  largest  weighed  seventeen 
pounds,  fell  upon  an  elliptical  surface  ranging 
from  southeast  to  northwest,  and  about  eleven  kil- 
ometres in  length.  These  stones  smoked,  they 
were  burning  hot,  without  being  on  fire,  and  it 
was  ascertained  that  it  was  easier  to  break  them 
within  a  few  days  after  their  fall  than  at  a  later 
period." 

METEORIC    STONES. 

Popular  tradition  being  thus  confirmed  by 
actual  experience,  all  that  could  be  remembered 
of  the  observations  of  the  ancients  was  brought 


METEORIC   STONES.  211 

together,  and  efforts  were  made  to  collect  new 
ones.  Howard,  an  English  chemist,  drew  up  a 
chronological  list  of  all  the  stones  that  had  thus 
fallen  from  the  sky  since  the  earliest  times.  This 
list  Chladni  has  completed.  We  select  from  it 
the  most  remarkable  instances  that  can  be  referred 
to  a  determinate  epoch : 

Before  the  Christian  Era. — The  thunder-stone 
that  fell  in  Crete,  and  was  held  in  veneration  as 
the  symbol  of  Cybele. — The  sudden  shower  of 
stones  which  destroyed  the  enemies  of  the  Jewish 
people  at  Beth-horon,  as  told  by  Joshua. — The 
sacred  shield  that  fell  in  the  reign  of  Numa. — 
The  black  stone  kept  in  the  Kaaba,  at  Mecca. — 
The  thunder-bolt,  hard  and  glittering,  from  which 
the  sword  of  Antar  was  fashioned. 

After  the  Christian  Era. — Fall  of  a  stone 
weighing  two  hundred  and  sixty  pounds  at  En- 
sisheim,  in  Alsace.  This  enormous  stone  was 
kept  for  a  long  time  on  the  altar  of  the  village 
church. — A  stone  of  black  metallic  color,  of  the  size 
and  form  of  a  human  head,  and  weighing  fifty-four 
pounds,  fell  on  Mount  Yaison,  in  Provence. — A 
stone  fell  in  a  fishing-boat  in  Copensha. — A  stone 
fell  at  Larissa,  in  Macedonia ;  this  stone,  which 
emitted  a  sulphurous  odor,  and  had  the  appearance 
of  iron  in  ebullition,  weighed  sixty-two  pounds. — 


212         METEORS   AND   METEORIC   PHENOMENA. 

A  great  shower  of  stones  at  Barbotan,  near  Roque- 
fort. Some  of  the  fragments  were  from  twenty- 
eight  to  thirty  pounds  in  weight;  one  of  them 
penetrated  a  cabin  and  killed  a  shepherd  and  a 
young  bull. — A  shower  of  stones  at  Cutro,  in  Ca- 
labria, during  the  fall  of  a  great  quantity  of  red 
dust. — Stony  masses  fell  in  the  Baltic  Sea  just 
after  the  great  Gottenburg  meteor. 

At  four  o'clock,  in  the  afternoon  of  the  13th  of 
September,  1$68,  there  was  seen  at  the  village  of 
Luce,  two  leagues  from  Chartres,  in  France,  a  dark 
cloud,  from  which  detonations  were  heard,  and 
these  were  followed  by  the  whistling  or  hissing 
sound  that  accompanied  the  fall  of  a  black  stone. 
The  latter,  which  nearly  buried  itself  in  the  soil, 
weighed  seven  pounds  and  a  half,  and  was  so  burn- 
ing hot  that  no  one  could  touch  it. — The  stone 
that  fell  at  Angers,  June  9,  1822,  was  attrib- 
uted to  a  beautiful  shooting-star  seen  at  Poi- 
tiers. Humboldt  relates  that  this  meteor  had  the 
effect  of  a  Roman  candle  in  a  display  of  fireworks, 
and  left  a  train  in  a  straight  line  of  such  glowing 
brilliancy  that  the  light  lasted  for  several  min- 
utes. 

AN   EXTRAORDINARY   METEOR. 

In  a  letter  addressed  to  M.  A.  Quetelet,  the 
permanent  secretary  of  the  Royal  Academy  of 


AN   EXTRAORDINARY   METEOE.  213 

Belgium,  with  regard  to  a  remarkable  meteor  ob- 
served at  Hurworth  in  October,  1854,  Sir  J.  Her- 
schel  quotes  the  following  description,  which  we 
give  substantially  as  it  appeared  in  the  Sheffield 
Times.  It  was  published  by  a  person  living  at 
Hurworth,  who,  in  company  with  his  brother,  saw 
the  phenomenon : 

"  My  brother  and  I  were  returning  home  at 
nine  o'clock  in  the  evening,  and  had  just  reached 
the  end  of  the  village,  and  were  about  to  cross  a 
meadow  of  considerable  breadth.  The  sky  was 
clear  and  starry,  but  dark.  We  were  looking  at  one 
of  the  brightest  constellations,  when,  at  the  very 
point  on  which  our  gaze  was  fixed,  we  beheld  a  mag- 
nificent sight.  A  cry  of  admiration  and  astonish- 
ment escaped  us  both.  What  we  saw  was  a  globe 
of  fire,  at  least  double  the  size  of  the  moon  when 
it  rises.  It  was  as  red  as  blood,  and  shot  out 
sparkling  rays,  which  were  marked  in  sharp  out- 
lines, as  old  engravings  represent  the  rays  of  the 
sun.  It  drew  after  it  a  long  trail  of  light  of  the 
most  beautiful  limpid  golden  color.  The  train 
had  no  resemblance  to  the  hairy  tail  of  a  comet, 
but  was  more  like  a  solid  column,  of  great  breadth 
and  perfect  compactness,  standing  out  against  the 
deep  blue  of  the  sky.  In  the  beginning  it  pre- 
sented the  appearance  of  a  straight  line,  but  as  it 


214:         METEORS   AND   METEORIC   PHENOMENA. 

mounted  the  heavens,  it  described  the  curve  of  an 
arch  with  sparkling  scintillations  of  great  inten- 
sity, which,  however,  did  not  pass  beyond  the 
well-defined  exterior  line.  Its  direction  was  from 
northeast  to  southwest,  and  its  length  so  enor- 
mous that,  when  its  nucleus  was  disappearing 
under  the  southwestern  horizon,  the  tail  was  still 
visible  at  the  northeast  in  all  its  original  splendor. 

"When  this  globe  of  fire  was  immediately 
above  us,  it  seemed  to  pause  for  a  moment  with 
vibrations  so  violent  that  I  was  afraid  it  would  fall 
on  us.  But,  the  next  instant,  I  saw  that  the  vibra- 
tion was  only  a  whirling  motion,  and  that  it  was 
turning  rapidly  on  its  axis,  passing  from  a  vivid 
fiery  red  to  the  deep  red  mentioned  above,  with- 
out, however,  losing  any  thing  of  its  general  ap- 
pearance. "We  continued  to  see  it,  looking  as 
brilliant  as  ever,  behind  the  trees  on  the  other  side 
of  the  village.  While  this  globe  was  passing  over 
us  it  seemed  a  little  smaller  than  when  it  first  ap- 
peared on  the  horizon,  no  doubt  because  of  its 
great  elevation,  just  as  the  sun  and  the  moon 
look  smaller  at  their  meridian  than  when  they 
are  rising. 

"  As  I  have  been,  for  a  long  time  past,  in  the 
habit  of  watching  the  stars,  I  have  seen  several 
brilliant  meteors,  but  never  any  that  could  bear 


AN   EXTRAORDINARY   METEOR.  215 

the  least  comparison  to  this  one,  whether  for  di- 
mensions or  for  splendor  and  duration.  Owing 
to  its  height  in  the  air,  it  must  have  been  visible 
at  a  great  distance,  and  I  hoped  that  it  would 
have  been  seen  and  described  by  intelligent  ob- 
servers. As  such,  however,  has  not  been  the  case, 
I  have  thought  it  my  duty  to  furnish  some  details 
concerning  a  phenomenon  so  grand  and  striking." 

According  to  Sir  John  HerscheFs  letter,  this 
phenomenon  was  seen,  in  like  manner,  by  many 
other  persons,  at  Darlington,  at  Durham,  and  at 
Dundee,  in  Scotland : 

"  It  is  quite  remarkable  that,  in  consulting  the 
register  which  records  the  observations  made  of 
the  famous  meteor  that  crossed  England  on  the 
18th  of  April,  1783,  we  found  that  it  was  seen  at 
Windsor  about  nine  o'clock,  which  was  precisely 
the  hour  at  which  we  saw  this  one,  my  brother 
having  looked  at  his  watch  at  the  moment  of  its 
appearance.  The  meteor  of  1783,  having  appeared 
during  the  twilight  of  a  summer  evening,  would, 
no  doubt,  have  been  more  generally  observed  than 
the  latter  phenomenon,  which  showed  itself  in  a 
dark  night  at  the  close  of  autumn.  But,  for  this 
very  reason,  the  latter  should  have  been  much 
more  brilliant  than  the  former  one,  and  it  is  to  be 

regretted  that  the  lateness  of  the  hour,  or  rather 
11 


216         METEORS   AND   METEORIC   PHENOMENA. 

of  the  season,  should  have  prevented  it  from  being 
as  generally  observed. 

"  No  noise,  accompanying  its  passage,  reached 
us.  Those  who  saw  the  enormous  globe  of  fire, 
sweeping  across  the  sky  with  inconceivable  veloci- 
ty, will  never  forget  that  magnificent  and  wonder- 
ful meteor.  In  beholding  unrolled  above  us  that 
splendid  train  of  light,  which  covered  more  than 
half  of  the  sombre  vault  of  the  heavens  with  a 
golden  arch,  we  involuntarily  thought  of  the  spec- 
tacle that  must  be  presented  to  the  eyes  of  the 
inhabitants  of  Saturn  by  the  ring  that  encircles 
that  planet.  The  tail,  near  where  it  ended,  broad- 
ened enormously ;  it  seemed  more  transparent, 
and  less  compact,  yet  with  well-defined  outlines, 
and  rounding  off  at  the  extremity.  The  illustra- 
tion accompanying  this  letter  was  sketched  with 
the  hope  of  attracting  general  attention  to  an  oc- 
currence so  interesting,  rather  than  with  any  pre- 
tension of  giving  even  a  feeble  idea  of  this  rare 
and  splendid  phenomenon." 

VELOCITY  AND  APPEARANCE  OF  BOLIDES. 

The  speed  of  these  fire-balls  is  now  calculated 
with  considerable  accuracy,  as  will  be  seen  from 
the  following  extract  taken  from  the  researches  of 
M.  Heiss,  the  director  of  the  Minister  Observatory. 


TELOCITY   AND   APPEARANCE   OF  BOLIDES.      217 

The  superb  bolide  which  he  describes  was  seen, 
on  the  14th  of  March,  1863,  in  Holland,  Belgium, 
Germany,  England,  and  France  : 

"Toward  seven  o'clock  in  the  evening,  the 
meteor  appeared  in  the  sky  like  a  shooting-star ; 
but,  little  by  little,  it  enlarged  until  it  presented 
an  apparent  surface  comparable  to  a  quarter  of  the 
moon,  and  a  brightness  that  made  the  stars  visible 
at  the  time  seem  pale.  After  having  illumined 
the  horizon  with  a  vivid  light,  which  different  ob- 
servers have  described  as  exhibiting  all  the  colors 
of  the  rainbow,  from  red  to  violet,  the  fire-ball  dis- 
appeared with  an  explosion.  In  many  places, 
sparks  and  a  train  were  seen.  The  duration  of 
the  phenomenon  was  about  five  seconds.  The 
trajectory,  directed  north  and  south,  was  inclined 
twenty-two  degrees  to  the  horizon,  and  the  length 
of  the  arc — described  from  the  point  of  inflamma- 
tion to  that  of  explosion,  at  about  twenty-six  kilo- 
metres (sixteen  and  three-quarter  miles)  above  the 
surface  of  the  ground — was  two  hundred  and 
eighty-five  kilometres  (one  hundred  and  seventy- 
seven,  nine-hundredths  miles).  This  indicated  a 
speed  of  one  hundred  and  sixty-three  kilometres 
(thirty-nine,  fourteen-hundredths  miles)  per  second. 
Four  hundred  and  twenty  yards  was  the  real  dia- 
meter of  the  blazing  globe,  which  must  have  been, 


218         METEOKS  AND   METEORIC   PHENOMENA. 

generally,  of  a  gaseous  nature,  with  no  solid  nu- 
cleus." 

It  is  this  extreme  velocity,  superior  to  that  of 
our  globe  in  its  orbit,  which,  with  the  resistance 
of  the  air,  accounts  for  the  appearances  presented 
by  these  fire-balls.  "  The  heat  which  the  meteor- 
ites possess,"  says  Sir  John  Herschel,  in  his  Astron- 
omy, "  when  they  fall  upon  the  soil,  the  igneous 
phenomena  that  accompany  them,  and  their  ex- 
plosion, when  they  penetrate  the  denser  layers  of 
the  atmosphere,  are  all  sufficiently  explained  by 
the  aid  of  physical  laws.  They  are  caused  by  the 
condensation  of  the  air,  occasioned  by  their  enor- 
mous swiftness  of  translation,  and  by  the  relations 
that  subsist  between  highly-rarefied  air  and  heat." 
The  explosion  is  attributed  to  the  pressure  sus- 
tained by  the  solid  mass.  Calculation  shows 
that,  at  the  height  of  eighteen  kilometres,  where 
the  density  of  the  air  is  ten  times  less  than  at  the 
surface  of  the  earth,  a  velocity  of  forty  kilometres 
would  produce  a  pressure  of  six  hundred  and 
seventy-five  atmospheres.  Iron  might  sustain 
this,  but  it  would  cause  a  stone  to  burst.  This 
calculation  is  confirmed  by  actual  observation : 
aerolites  composed  almost  exclusively  of  iron  come 
to  the  ground  entire,  but  such  as  are  of  less  solid 
consistency  fall  in  fragments. 


VELOCITY  AND  APPEARANCE  OF  BOLIDES.      219 

On  the  14th  of  October,  1863,  about  three 
o'clock  in  the  morning,  ]VT.  J.  Schmidt,  director  of 
the  Athens  Observatory,  succeeded  in  following  a 
very  remarkable  bolide  with  the  telescope.  The 
meteor  in  question  appeared  like  a  shooting-star, 
rather  slow  in  movement,  between  the  constella- 
tions of  the  Hare  and  the  Dove.  "  It  soon  surpassed 
Sirius  in  splendor.  Its  color  was  a  clear  yellow.  It 
passed  Eridanus  toward  the  west,  shedding  a  light 
so  extraordinary  that  all  the  stars  were  eclipsed, 
while  the  city  of  Athens,  the  country,  and  the  sea, 
looked  as  though  on  fire.  The  Acropolis  and  the 
Parthenon  stood  out,  a  dead  greenish-gray  in  hue, 
against  a  background  of  golden-green  sky." 

At  this  moment  M.  Schmidt,  resorting  to  his 
telescope,  was  enabled  to  observe  the  meteor  for 
several  seconds,  and  note  a  curious  phenomenon  : 
There  was  not  merely  a  single  luminous  body  to 
be  seen,  but  he  discovered  two  brilliant  bolides 
of  a  greenish-yellow,  in  the  form  of  elongated 
drops  :  the  larger  preceded  the  smaller,  and  each 
left  a  red  track,  with  well-defined  edges.  These 
two  bodies  were,  moreover,  followed  by  luminous 
bodies  of  less  size  and  similar  appearance,  irregu- 
larly distributed,  like  sparks  in  the  train  of  the 
bolides.  At  the  moment  of  its  disappearance,  the 
meteor  appeared  divided  into  four  or  five  frag- 


220         METEORS  AND   METEORIC   PHENOMENA. 

ments,  of  a  dark  red.     !N"o  noise  was  heard  either 
before  or  after  the  disappearance. 

FALL   OP   AEROLITES. 

We  will  cite,  in  addition,  some  details  con- 
cerning a  more  recent  appearance  of  bolides  and 
the  fall  of  aerolites  in  the  south  of  France : 

"  Yesterday  (May  14,  1864),  at  eight  o'clock  in 
the  evening,"  writes  an  observer  at  Castillon,  in 
the  department  of  the  Gironde,  "a  magnificent 
meteor  was  seen  by  us  in  the  vicinity  of  the  moon, 
and  in  an  easterly  course.  It  was  visible  for 
about  five  seconds,  during  which  time  it  swept 
over  an  arc  of  more  than  sixty  degrees.  At  last 
it  burst  into  smaller  stars  and  disappeared. 

"  The  apparent  size  of  the  meteor  constantly 
increased  by  progressive  augmentations.  A  mo- 
ment before  disappearing,  its  diameter  seemed 
equal  to  at  least  half  that  of  the  moon.  At  first, 
the  light  had  a  greenish-blue  tinge ;  then  it  be- 
came white,  and  shone  with  such  brilliancy  that 
persons  badly  situated  for  a  direct  view  of  the 
meteor,  thought  they  had  seen  the  reflection  of  a 
vivid  and  prolonged  flash  of  lightning." 

In  many  places  distant  from  each  other,  aloud 
detonation  was  heard,  and  an  interval  of  some  du- 
ration elapsed  between  the  visible  explosion  of 


FALL   OF   AEROLITES.  221 

the  meteor  and  the  hearing  of  the  noise.  Three 
or  four  minutes  were  counted,  and  only  two  min- 
utes correspond  to  a  vertical  distance  of  forty  kil- 
ometres. The  atmospheric  layers  at  that  height 
are  greatly  rarefied,  and,  in  order  that  an  explo- 
-sion  taking  place  in  those  regions  should  cause  a 
noise  of  such  intensity  at  the  surface  of  the  earth, 
and  over  a  horizontal  extent  so  considerable,  we 
must  admit  that  it  exceeded  in  violence  any  thing 
known  to  us. 

Judging  by  the  apparent  height  and  dimen- 
sions of  the  fire-ball,  its  diameter  was  estimated 
to  be  from  four  hundred  to  five  hundred  yards. 
It  was  then  four  or  five  times  the  size  of  the  Paris 
cathedral.  M.  Lauss£dat  calculated  that  its  ve- 
locity was  fifteen  miles  per  second,  or,  in  other 
words,  about  two-thirds  of  the  rapidity  of  the 
earth  in  its  orbit.  Aerolites  have  been  picked 
up  near  Orgeuil,  in  the  department  of  Lot-et- 
Garonne,  and  in  many  neighboring  places.  M. 
Daubree,  who  examined  them,  found  that  they  re- 
sembled terrene  lignites.  "  In  this  black  mass," 
he  says,  "  may  be  distinguished  small  particles 
of  a  metallic  substance,  of  a  bronzed-yellow  color, 
the  density  of  which  allows  them  to  be  isolated  by 
washing.  Examining  these  little  grains  with  a 
microscope,  I  recognized  some  very  compact  crys- 


222         METEORS   AND   METEORIC    PHENOMENA. 

talline  forms,  but  of  very  small  dimensions.  These 
grains,  or  particles,  are  very  strongly  attracted  by 
the  magnet,  and  possess  all  the  physical  and  chem- 
ical characteristics  of  the  magnetic  pyrites  dis- 
covered forty  years  ago  in  the  meteoric  stone  of 
Juvinas.  The  meteorite  of  Orgeuil  should  be 
classified  with  the  coaly  meteors,  of  which  the  fall 
of  three  only  has  thus  far  been  recorded.  The 
surface  of  all  the  fragments  was  found  to  be  fused 
and  vitrified  ;  however,  the  interior  included  sub- 
stances which  could  easily  be  volatilized.  These 
two  circumstances,  apparently  contradictory,  may 
be  explained,  if  it  be  admitted  that  the  heat  un- 
dergone by  the  meteorites  was  of  such  brief  dura- 
tion that  it  could  not  penetrate  the  interior  of  the 
mass,  the  substance  of  which,  moreover,  was  a  bad 
conductor  of  caloric.  In  the  case  to  which  we 
are  now  referring,  the  heat  must  have  been  in 
some  sort  instantaneous,  yet  of  considerable  in- 
tensity, for  it  required  the  red-white  heat  of  the 
blow-pipe  to  reproduce  artificially  the  varnishy 
melted  surface  that  is  left  by  fusion.  Not  only  is 
the  interior  part  of  the  meteorite  tender  and  friable, 
but  it  is  reduced  to  impalpable  powder,  the  mo- 
ment that  it  comes  in  contact  with  water,  and  the 
soluble  salt  that  serves  to  cement  it  is  dissolved." 


COMPOSITION   OF   AEROLITES.  223 

COMPOSITION    OF    AEROLITES. 

In  studying  aerolites,  and  comparing  them 
with  other  minerals,  savants  have  arrived  at  the 
conclusion  that  they  are  indeed  composed  of  the 
same  elements  (nearly  a  third  of  the  known  simple 
bodies),  but  that,  in  the  method  of  aggregation, 
they  are  entirely  different,  and  must  be  regarded 
as  strangers  to  our  globe.  Whatever  may  be  the 
date  or  locality  of  their  fall,  they  have  very 
evident  common  characteristics,  and  this  relation 
is  so  striking  that  they  might  have  been  regarded 
as  having  formed  part  of  the  same  rock :  on  the 
outside,  a  black  incrustation,  a  glistening  enamel, 
produced  by  very  high  temperatures,  but  penetrat- 
ing only  a  few  hair-breadths ;  and,  in  the  interior, 
a  singular,  granulated  structure,  presenting  some 
very  strange  features,  which,  when  polished,  might 
be  compared  to  hieroglyphics.  An  aerolite  often 
resembles  a  stone  at  which  shot  had  been  fired. 
The  granulations  are  sometimes  extremely  diminu- 
tive, as  in  the  specimen  described  above ;  some- 
times, as  large  as  millet,  as  peas,  or  even  as  hazel- 
nuts.  They  are  hard,  and,  when  broken,  exhibit 
crystallization.  The  matter  in  which  they  are  in- 
crusted  is  of  an  earthy  nature,  more  or  less  con- 
sistent, and  ordinarily  gray.  The  substances  that 


224:         METEORS  AND   METEOEIO   PHENOMENA. 

compose  it  are  for  the  most  part  mechanically 
mixed,  and  not  chemically  combined.  Aerolites 
composed  almost  entirely  of  iron  are  put  in  a 
class  apart  from  the  rest,  so  that  they  may  be  de- 
composed in  grains.  It  must  be  remarked  that 
this  iron  is  in  nowise  oxidated  ;  that  it  is,  as  miner- 
alogists say,  in  its  native  state,  and  that,  with 
the  nickel,  which  it  most  usually  holds  in  combi- 
nation, stamps  aerolites  with  a  mark  altogether 
peculiar  in  its  way. 

Stony  aerolites,  formed  by  the  mixture  of  dif- 
ferent mineral  substances,  constantly  have  the  ap- 
pearance of  fragments,  and  they  are  not  found  in 
large  masses,  like  those  which  are  almost  entirely 
composed  of  iron.  There  have  been  some  enor- 
mous specimens  among  the  last.  The  meteoric 
mass  observed  by  Pallas,  on  the  plains  of  Siberia, 
weighed  one  thousand  five  hundred  and  forty 
pounds.  It  was  held  in  veneration  by  the  Tar- 
tars, and  regarded  by  them  as  having  fallen  from 
heaven.  A  mass,  found  in  Brazil,  weighed  fully 
six  tons  and  six-tenths.  According  to  M.  Beudant, 
there  is  a  similar  mass,  weighing  fifteen  tons  and 
eight  hundred  pounds,  at  Olimpa,  in  the  Tucuman 
country,  and  one  of  fifteen  and  nine-tenths  tons  in 
the  environs  of  Durango  in  Mexico.  In  the  east- 
ern part  of  Asia,  not  far  from  the  source  of  the 


COMPOSITION    OF   AEROLITES.  225 

Yellow  River,  there  is  a  mass  about  forty  feet  in 
height,  according  to  the  statement  of  Abel  Remu- 
sat.  The  Mongols  call  it  the  Rock  of  the  Pole, 
and  say  that  it  fell  after  the  appearance  of  a 
meteor.  The  only  aerolite  of  this  character,  the 
celestial  origin  of  which  is  ascertained,  fell  near 
Agram,  in  Dalmatia,  on  the  26th  of  May,  1751. 

The  most  remarkable  aerolite  which  the 
mineralogical  galleries  of  the  French  Museum 
possess,  is  that  of  Privas,  in  Ardeche.  It  fell  on 
June  5,  1821,  weighs  two  hundred  and  two  and 
four-tenths  pounds,  and  buried  itself  more  than 
seven  inches  in  the  ground.  An  approximative 
calculation,  based  upon  data  collected  since  they 
have  been  observed  with  greater  care,  estimates 
the  number  of  meteoric  descents  at  about  six 
hundred  annually.  The  rocks  of  native  iron, 
resting  on  the  soil  in  different  parts  of  the  globe, 
and  not  homogeneous  with  the  surrounding  land, 
are  also  probably  aerolites. 

Usually,  the  aerolites  which  people  have  suc- 
ceeded in  touching  at  the  moment  of  their  fall, 
were  very  hot,  but  one  was  recently  noted  in  the 
Punjaub  that  froze  the  hands  of  those  who  at- 
tempted to  pick  it  up.  It  is  easy  to  explain  this 
low  temperature,  if  we  admit  that  these  bodies 
have  traversed  the  interplanetary  spaces,  where, 


226         METEORS   AMD   METEORIC   PHENOMENA. 

according  to  some  physiologists,  the  temperature 
descends  to  one  hundred  and  forty  degrees.  The 
passage  through  our  atmosphere  heats,  as  we  have 
seen,  only  the  surface  of  the  meteoric  mass,  which, 
in  breaking,  lets  fall  fragments  of  the  central  part, 
that  retains  its  very  low  temperature.  In  metallic 
aerolites,  the  transmission  of  the  enormous  ex- 
ternal heat  is  very  rapid,  and  they  often  reach  the 
earth  in  the  condition  of  red-hot  balls. 

PERIODICAL  DISPLAYS. 

When  the  celestial  origin  of  these  meteoric 
bodies  was,  at  last,  recognized,  it  was  thought 
that  they  might  come  from  the  moon,  and  that 
they  were  the  product  of  its  volcanoes.  It  was 
calculated  that,  in  order  to  cause  them  to  pass  be- 
yond the  limit  of  our  satellite's  attraction,  a  force 
double  that  which  projects  the  ball  from  our 
heaviest  cannon  would  suffice.  They  would  then 
come  near  enough  to  revolve  around  the  earth, 
and  sometimes  be  drawn  to  its  surface.  But  this 
explanation  did  not  account  for  the  new  appear- 
ances that  we  are  about  to  mention,  and  which 
have  led  to  a  more  general  hypothesis.  These 
appearances  embrace  the  flood  of  meteors  which 
illuminates  the  heavens  at  different  periods  of  the 
year,  and  of  which  the  displays  offer  a  remarkable 


PERIODICAL    DISPLAYS.  227 

element  of  periodicity.  Olmstead  and  Palmer 
have  given  descriptions  of  the  enormous  shower 
of  falling-stars  which  they  saw  in  America  during 
the  night  between  the  12th  and  13th  of  Novem- 
ber, 1833.  The  meteors  fell  like  snow-flakes,  and, 
in  the  lapse  of  nine  hours,  the  number  seen  from 
one  station  was  estimated  at  more  than  two  hun- 
dred thousand.  They  shone  with  various  colors  ; 
fire-balls  of  all  dimensions  were  mingled  with 
them,  and  in  the  depth  of  the  firmament  light 
phosphorescent  traces  were  detected.  In  1799,  at 
the  same  period  of  the  year,  Humboldt  had  wit- 
nessed a  phenomenon  nearly  as  brilliant,  at  Cu- 
mana.  In  1823,  and  again  in  1832,  a  similar  one 
was  seen  in  Europe,  and  it  was  then  observed 
regularly  every  year  until  1842.  But  from  that 
year  the  date  of  its  appearance  became  displaced 
and  pushed  on  toward  the  close  of  October.  At 
the  same  time,  the  phenomenon  had  greatly  di- 
minished, and  had  even  entirely  disappeared. 

Such  was  not  the  case  in  reference  to  another 
date,  which  is  kept  up  with  great  precision.  It  is 
the  10th  of  August,  or  rather  it  covers  the  space 
from  the  9th  until  the  llth  of  that  month.  Un- 
questionable documents  establish  the  fact  that  the 
Chinese  astronomers  observed  showers  of  shooting- 
stars  more  than  ten  centuries  ago,  at  the  same 


228         METEORS   AND   METEORIC   PHENOMENA. 

periodical  date,  and  for  a  long  series  of  years.  In 
France,  the  popular  tradition  relative  to  the  fiery 
tears  of  Saint  Lawrence  on  his  fete  day,  the  10th 
of  August,  indicates  under  a  legendary  form  the 
periodical  return  of  these  showers  of  meteors. 
M.  Herrick  (Arago  quoting  him)  states  that,  ac- 
cording to  an  old  tradition  popular  in  Thessaly, 
in  the  midst  of  the  mountainous  countries  that 
surround  Mount  Pelion,  the  sky  opens  during  the 
night  of  August  6th,  the  festival  of  the  Transfigu- 
ration, and  torches  are  visible  through  the  orifice. 

The  most  recent  investigations  show  that,  dur- 
ing the  greater  part  of  our  century,  the  phenome- 
non has  recurred  with  constant  regularity,  and  has 
been  visible  over  the  entire  globe. 

M.  Quetelet,  in  a  learned  memoir  on  the 
"  shooting-stars  of  the  10th  of  August  period,  in 
1863,"  reproduces  the  following  letter  from  Sir 
John  Herschel : 

"As  for  my  opinion  concerning  these  enig- 
matical phenomena  (that  is  to  say,  so  far  as  the 
question  of  their  origin  inside  or  outside  of  our 
atmosphere  goes),  I  could  not  but  admit  the  ne- 
cessity of  attributing  them  to  a  cosmic  origin. 
Otherwise,  I  can  see  no  explanation,  in  the  least 
degree  admissible  in  any  other  quarter,  of  the 
persistence  from  year  to  year  of  the  same  point  of 


PERIODICAL   DISPLAYS.  229 

radiation  in  contrast  with  others,  nor  of  the  regu- 
lar recurrence  on  the  same  day  of  the  year  (Au- 
gust 10th),  unless  by  the  earth  meeting  with  a 
belt  of  '  something '  revolving  around  the  sun. 
Without  doubt  this  explanation  leaves  something 
yet  to  be  explained,  but  it  satisfies  the  two  grand 
conditions  of  the  problem,  and  these  two  grand 
conditions  are  the  most  striking.  As  to  their 
great  elevation  above  the  earth,  it  leads  us  to  sus- 
pect the  existence  of  a  kind  of  atmosphere  higher 
up  than  the  aerial  atmosphere,  lighter,  and,  so  to 
speak,  more  igneous  than  our  own." 

M.  Quetelet's  important  work,  entitled  "  Phy- 
sique du  Globe,"  published  in  1861,  designates 
these  two  atmospheric  strata  of  different  consist- 
ency as  the  movable  atmosphere,  subject  to  varia- 
tions of  all  kinds,  and  the  immovable  atmosphere, 
of  very  feeble  density,  which  remains  in  a  condi- 
tion of  relative  stability,  or  fixedness.  "  This  up- 
per atmosphere,  favorable  to  the  combustion  and 
to  the  brilliance  of  the  shooting-stars,  would  not 
necessarily  be  of  the  same  nature  and  the  same 
composition  as  the  lower  atmosphere  in  which  we 
live." 

M.  Quetelet  also  calls  attention  to  the  fact, 
that  the  very  existence  of  the  shooting-stars  natu- 
rally leads  to  the  admission  that  the  height  of  the 


230         METEOES   AND   METEOEIC   PHENOMENA. 

atmosphere  must  be  at  least  three  or  four  times 
what  it  is  now  supposed  to  be. 

OBSCURATION   OF   THE    SUN. 

"  The  sun's  disk,"  says  Arago,  in  his  "  Popular 
Astronomy,"  under  the  head  of  Cosmic  Meteors, 
"  is  sometimes  obscured  for  a  few  moments,  and  its 
light  becomes  enfeebled  to  such  a  degree  that  the 
stars  may  be  seen  at  noonday.  Humboldt  recalls 
the  circumstance  that  a  phenomenon  of  this  kind, 
which  could  not  be  ascribed  either  to  fog  or  to 
volcanic  cinders,  took  place  in  1547,  about  the  time 
of  the  disastrous  battle  of  Muhlberg,  and  lasted 
three  days.  Kepler  was  disposed  to  trace  the 
cause  of  it  to  the  interposition  of  a  materia  comet- 
ica,  or  such  matter  as  composes  the  train  of  com- 
ets, or  to  a  black  cloud  which  sooty  emanations 
from  the  sun  had  contributed  to  form.  Chladni 
and  Schnurrer  attributed  it  to  the  passage  of  me- 
teoric masses  over  the  disk  of  the  sun,  like  the 
phenomena  of  this  kind  that  occurred  in  1090  and 
1208,  although  they  were  of  shorter  duration,  the 
first  one  lasting  three  and  the  second  six  hours 
only. 

"Messier  relates  that,  on  the  17th  of  June, 
1777,  about  noon,  he  saw  a  prodigious  number  of 
black  globules  pass  before  the  sun.  Did  not  these 


THE   BELT   OF   METEORITES.  231 

globules  form  part  of  one  of  the  rings  of  asteroids 
of  which  all  observations  of  cosmic  meteors  tend 
to  make  us  admit  the  existence  ?  Two  other  ob- 
scurations of  the  sun — that  in  the  beginning  of 
February,  1106,  and  that  of  May  12,  1706,  dur- 
ing which,  about  ten  o'clock  in  the  morning,  the 
darkness  became  such  that  the  bats  began  to  fly 
about — seem  likewise  inexplicable  by  any  other 
theory." 

THE   BELT   OF   METEORITES. 

According  to  M.  Faye,  the  meteoric  display 
of  November,  and  that  of  several  other  months, 
may  be  connected  in  the  following  manner  with 
the  one  seen  in  August :  The  earth,  in  its  passage 
through  the  belt  of  unknown  bodies  revolving 
around  the  sun,  carries  along  with  it,  by  its  pow- 
er of  attraction,  a  great  number  of  those  bodies, 
which  thenceforth  become  her  veritable  satellites. 
This  collection  burns  in  the  atmosphere,  in  the 
course  of  the  year,  and  precipitates  itself  upon  our 
planet's  surface.  During  their  circulation  in  our 
orbit  some  of  these  meteorites  may  pass  singly, 
like  those  that  are  seen  every  evening.  Others, 
assembled  in  different  groups,  approach  or  recede, 
according  to  their  position  in  the  orbit  that  they 
follow,  and  occasion  the  displays  of  November 


232         METEORS  AND  METEORIC   PHENOMENA. 

and  other  times  whose  periodicity  is  kept  up 
during  only  a  limited  number  of  years.  This  hy- 
pothesis would  explain  the  appearance  of  swarms 
of  satellites  seen  in  a  single  quarter  of  the 
heavens. 

The  ingenious  opinions  which  we  have  just 
summed  up  may  enable  the  reader  to  judge  of  the 
lively  interest  that  attaches,  at  the  present  time, 
to  what  M.  Faye  calls  "  the  mystery  of  the  shoot- 
ing-stars." Scarcely  the  first  veil  that  enshrouded 
it  has  yet  fallen,  indeed ;  but  observers  multiply 
in  number  and  combine  their  efforts,  and  learned 
men  are  uniting  their  labors,  sustained  by  the 
profound  feeling  that  inspired  the  following  pages 
from  the  pen  of  Humboldt : 

"  To  see  motion  rise  suddenly  in  the  midst  of 
the  calm  of  night,  and  for  a  moment  disturb  the 
tranquil  radiance  of  the  starry  vault;  to  follow 
with  the  eye  the  meteor  which,  in  falling,  traces 
its  luminous  trajectory  athwart  the  firmament — 
is  not  this  to  have  one's  thoughts  ascend,  straight- 
way, to  those  infinite  spaces  which  are  filled 
everywhere  with  matter,  and  everywhere  vivified 
with  movement?  Of  what  consequence  is  the 
diminutive  size  of  these  meteors  in  a  system 
where,  along  with  the  enormous  volume  of  the 
sun,  one  finds  atoms  as  small  as  Ceres,  or  as  the 


THE  BELT   OF   METEORITES.  233 

first  satellite  of  the  planet  Saturn  ?  What  matters 
their  sudden  disappearance  when  a  phenomenon 
of  another  order,  the  extinction  of  those  stars  that 
shone  all  at  once  in  Cassiopeia,  in  the  Swan,  and 
in  Serpentarius,  has  already  forced  us  to  admit 
that  there  may  exist  in  the  celestial  spaces  other 
stars  than  those  that  we  always  see  there  ?  We 
know  the  fact,  now,  that  shooting-stars  are  aggre- 
gations of  matter,  veritable  asteroids,  that  circulate 
around  the  sun,  which,  like  comets,  sweep  across 
the  orbits  of  the  larger  planets,  and  shine  near  our 
atmosphere,  or,  at  least,  in  its  highest  strata. 

"  Isolated  upon  our  planet  from  all  parts  of  the 
creation  which  the  limits  of  our  atmosphere  do  not 
embrace,  we  are  not  in  communication  with  the 
celestial  bodies,  excepting  by  the  rays  of  heat  and 
light,  and  by  that  mysterious  attraction  which 
those  distant  masses  exert  upon  our  globe,  our 
seas,  and  even  the  beds  of  air  that  surround  us. 
But,  if  aerolites  and  shooting  -  stars  be  really 
planetary  asteroids,  the  method  of  communication 
changes :  it  becomes  more  direct,  and,  in  some 
sort,  assumes  a  material  shape.  In  fact,  we  no 
longer  have  to  deal  with  those  far  remote  bodies, 
the  action  of  which,  upon  the  earth,  is  limited  to 
the  production  of  luminous  or  calorific  vibrations, 
or  motions  in  accordance  with  the  laws  of  a  re- 


234:         METEOKS    AND   METEORIC   PHENOMENA. 

ciprocal  attraction  of  gravitation.  We  now  have 
before  our  contemplation  material  bodies,  which, 
abandoning  the  celestial  spaces,  traverse  our  at- 
mosphere, and  dash  against  the  earth,  and  thence- 
forth form  a  portion  of  it.  Such  is  the  only  cos- 
mical  event  that  can  put  our  planet  in  contact 
with  the  other  parts  of  the  universe.  Accustomed 
as  we  are  to  know  things  placed  outside  of  our 
globe  only  through  the  medium  of  measurement, 
calculation,  and  reasoning,  we  are  now  surprised 
at  being  able  to  touch  them,  weigh  them,  and 
analyze  them.  It  is  thus  that  science  brings  the 
secret  springs  of  the  imagination  and  the  living 
forces  of  the  mind  into  play  in  our  souls,  while  the 
vulgar  throng  behold  in  these  phenomena  but 
sparks  that  flash  up  and  then  die  out,  and  in  these 
black  stones,  that  fall  with  a  crash  from  the  bosom 
of  the  clouds,  nothing  but  the  coarse  product  of 
some  convulsion  of  Nature." 


CHAPTEK  X. 

DUST  IN  THE  ATMOSPHERE.— DRY  FOGS. 


Cosmic  Dust.— Volcanic  Ashes.— The  Sauds  of  the  Deserts.— The  Bed 
Mists  of  Cape  Verde.— Showers  of  Manure.— Dry  Fogs. 


COSMIC  DUST. 

A  COSMIC  origin  must  be  assigned  to  a  great 
deal  of  the  dust  that  falls  from  the  atmosphere. 
Not  only  have  aerolites  of  very  slight  consistency 
been  picked  up,  but  many  savants  think  that  the 
appearance  of  bolides  is  often  due  to  bodies  of 
dusty  consistency  traversing  the  celestial  spaces. 
This  hypothesis  was  announced,  in  1849,  by  M. 
Heiss,  in  his  work  upon  periodical  shooting-stars. 
"  It  is  easily  understood,"  says  M.  Haidinger,  in 
an  interesting  memoir,  "  that  agglomerations  of 
dusty  matter,  collected  in  a  globular  form,  and 
passing  through  the  upper  strata  of  the  atmos- 
phere, first  excite,  in  their  totality,  certain  lumi- 
nous phenomena.  But  they  must  soon  be  resolved 


236         METEOKS    AND   METEORIC    PHENOMENA. 

again  into  dust,  leaving  nothing  in  existence  that 
could  determine  a  development  of  light.  We 
would  here  recall  the  fact  that,  according  to  M. 
Julius  Schmidt,  the  most  luminous  meteors  seem 
to  blaze  up  at  more  considerable  heights,  while 
those  of  less  intense  brightness  belong  to  less  ele- 
vated regions.  The  different  modes  of  the  diffu- 
sion of  their  light  may  be  attributed  to  the  greater 
or  less  volume  of  the  particles.  The  smallest 
grains  of  dust  emit  light  so  soon  as  they  reach  the 
upper  strata,  and  die  out  just  as  quickly,  because, 
after  a  short  course,  they  are  dispersed  by  the  re- 
sistance of  the  atmosphere.  The  less  diffused 
particles  make  a  longer  run,  but  they  also  die 
out,  generally  at  considerable  heights." 

The  great  meteors  that  descend  to  the  lower 
strata,  and  are  seen  to  have  a  rotary  movement, 
and  disappear  without  causing  a  fall  of  aerolites, 
may  be  considered  as  relatively  voluminous  ag- 
glomerations of  dusty  matter.  They  frequently 
leave  behind  them  luminous  trains  that  last 
for  some  time.  Admiral  Krusenstern,  in  his 
voyage  around  the  world,  saw  the  broad  track  of 
a  bolide  shining  for  more  than  an  hour,  without 
seeming  to  change  place  to  any  perceptible  de- 
gree. We  have  mentioned  the  clouds  that  are  seen 
during  the  daytime  in  the  track  of  meteors.  Mr. 


COSMIC   DUST.  237 

B.  Y.  Marsh,  describing  the  one  that  appeared  on 
the  15th  of  November,  1859,  in  a  part  of  America, 
says  that  it  left  a  column  of  smoke  about  a  thou- 
sand feet  in  diameter,  the  base  of  which  was  at  an 
elevation  of  nearly  eight  thousand.  These  ap- 
pearances can  be  explained  only  by  supposing  the 
presence  of  immense  masses  of  dusty  matter. 

M.  von  Reichenbach,  who  has  paid  much  at- 
tention to  aerolites,  has  published  some  remark- 
able studies  in  reference  to  their  relations  with 
comets,  which  he  considers  as  being  composed  of 
the  same  material  reduced  to  very  minute  parti- 
cles widely  separated  from  each  other.  The  con- 
densation of  these  clouds  of  cosmic  dust  at  differ- 
ent degrees,  seemed  to  him  to  explain  the  granu- 
lated appearance  observed  in  meteoric  stones,  and 
even  in  masses  of  iron  which  he  succeeded  in 
separating  into  globules. 

The  fall  of  dust,  the  matter  of  which  was  iden- 
tical with  that  of  aerolites,  has  been  ascertained, 
beyond  a  doubt,  by  recent  chemical  analysis,  as 
well  as  by  quite  a  number  of  historical  accounts. 
Pliny  affirms  that  "  a  fire  was  seen  to  fall  from 
heaven  in  a  shower  of  blood."  This  fire  must 
have  been  the  light  emanating  from  a  bolide,  and 
the  blood  a  reel  (dust  mixed  with  the  rain.  In 

Procopius,  there  is  mention  made  of  a  great  fall 
12 


238         METEOKS    AND   METEORIC    PHENOMENA. 

of  black  dust  in  the  environs  of  Constantinople,  in 
the  year  472 ;  it  must  have  accompanied  a  lumi- 
nous meteor,  since,  according  to  the  historian, 
"  the  heavens  seemed  on  fire.'r 

Arago  has  compiled  many  similar  facts  in  his 
"  Popular  Astronomy."  He  mentions  the  fall  of 
red  and  blackish  matter  that  took  place  at  Yerde, 
in  Hanover,  and  was  accompanied  by  a  globe  of 
fire  and  violent  detonations.  This  matter  burned 
the  wood-work  upon  which  it  fell.  On  March  14, 
1813,  red  dust  and  red  snow  fell  in  Calabria,  Tus- 
cany, and  Friuli,  and,  at  the  same  time,  a  great 
noise,  and  the  falling  of  stones,  were  heard  at 
Cutro.  Sementini  found,  in  several  specimens  of 
this  dust,  the  ordinary  chemical  composition  of 
aerolites. 

In  November,  1819,  a  black  rain  and  snow  fell 
at  Montreal,  and  in  the  northern  part  of  the  United 
States.  This  fall  was  accompanied  by  an  extraor- 
dinary darkening  of  the  sky,  shocks  similar  to 
those  felt  during  an  earthquake,  detonations,  and 
very  powerful  flashes  of  lightning.  Some  persons 
have  attributed  these  phenomena  to  the  conflagra- 
tion of  forests,  but  the  noise,  the  shocks,  and  all 
the  circumstances,  go  to  show  that  it  was  a  real 
meteor. 

The  American  sea-captain  Callam  reports  a 


VOLCANIC   ASHES. 

curious  observation  made  by  him.  His  ship  was 
in  the  Indian  Ocean,  to  the  southward  of  Java, 
when  a  shower  of  very  small  stones  fell  suddenly 
on  the  deck,  without  the  occurrence  of  any  other 
phenomenon  to  explain  this  odd  circumstance. 
He  picked  up  several  fragments,  and  Commander 
Maury,  to  whom  he  gave  them  on  his  return  to 
America,  sent  them  to  M.  Ehrenberg,  who,  by  the 
aid  of  a  powerful  microscope,  ascertained  that  the 
matter  of  these  fragments  had  originally  been 
liquid,  but  had  been  solidified  during  its  descent. 
It  offered  complete  resemblance  to  the  residue  re- 
sulting from  the  combustion  of  a  steel  wire  burned 
in  a  flask  full  of  oxygen  ;  and  this  leads  us  to  in- 
fer that  the  fragments  were  drops  of  water  falling 
from  the  incandescent  surface  of  an  aerolite  which 
had  passed  above  the  ship. 

VOLCANIC   ASHES. 

Clouds  of  dust  rise  from  the  bosom  of  the 
earth,  also,  that  frequently  spread  through  a  great 
breadth  of  atmosphere.  These  are  the  volcanic 
ashes,  which,  sometimes  scattered  by  the  winds, 
and  sometimes  falling  in  dense  showers  on  the 
soil,  bury  whole  cities  beneath  them.  The  follow- 
ing narrative  of  the  most  memorable  of  these  ca- 
tastrophes will  give  an  idea  of  the  phenomenon  : 


24:0          METEORS   AND    METEORIC    PHENOMENA. 

"  In  T9,  under  the  Emperor  Titus,  Pliny  tlie 
naturalist  was  in  command  of  the  Roman  fleet, 
near  Cape  Misenum,  westward  of  Naples.  His 
sister,  the  mother  of  Pliny  the  Younger,  drew  his 
attention  one  evening  to  a  cloud  of  extraordi- 
nary size  and  shape.  This  cloud,  after  rising  in  a 
vertical  column,  expanded  at  the  top  and  assumed 
the  appearance  of  a  spreading  pine-tree.  Pliny 
ordered  out  a  boat  and  went  rapidly  toward  Ye- 
suvius,  from  which,  as  was  soon  perceived,  this 
cloud,  or  rather  this  smoke,  ascended.  The  dense 
shower  of  cinders,  pumice-stone,  and  fragments 
of  rock,  hurled  from  the  crater,  was  already  terri- 
fying the  neighboring  country-people,  but  the 
naturalist  advanced  boldly  to  the  scene  of  danger. 
Near  Stabia,  he  passed  the  night  in  a  villa,  and, 
being  much  fatigued,  slept  so  profoundly  that  his 
breathing  could  be  heard  outside.  When  he 
awoke,  it  was  only  with  some  difficulty  that  he 
could  leave  the  house,  the  cinders  having  nearly 
choked  up  the  doorway.  At  the  break  of  day, 
which  the  eruption  rendered  nearly  as  dark  as 
night,  he  tried  to  advance  nearer  to  the  moun- 
tain, in  order  to  observe  the  phenomenon.  The 
flames  and  sulphurous  vapors,  that  made  every- 
body else  recoil,  only  stimulated  his  ardent  cour- 
age. But,  soon  afterward,  he  was  seen  striving  to 


VOLCANIC   ASHES.  241 

rise  from  the  spot  where  he  had  sat  down  for  a 
moment,  and  then  suddenly  fall,  struck  with  apo- 
plexy or  suffocated  by  the  fumes." 

It  may  be  remembered  that  during  this  vio- 
lent eruption  the  cities  of  Pompeii,  Stabia,  and 
Herculaneum,  disappeared,  the  first  two  under  a 
mass  of  cinders  and  scoriae,  and  the  latter  beneath 
the  lava.  They  remained  thus  buried  for  seven- 
teen hundred  years,  and  their  exact  site  was  no 
longer  remembered,  when,  by  accident,  they  were 
again  discovered." 

Captain  Basil  Hall  reports  the  following: — 
"  On  the  1st  of  May,  1812,  after  some  violent 
detonations,  that  terrified  the  inhabitants  of  Bar- 
badoes,  a  black  cloud  was  descried,  seaward,  upon 
the  northern  horizon.  Ere  long,  it  covered  the 
whole  sky,  which  had  just  been  emerging  from  the 
shadows  of  morning  twilight.  At  length,  the 
darkness  became  such  that  it  was  impossible,  in- 
doors, to  tell  where  the  windows  were,  while,  in 
the  open  air,  many  persons  could  not  see  either 
the  trees  near  which  they  were  passing,  the  out- 
lines of  the  neighboring  houses,  or  even  white 
handkerchiefs  placed  a  few  inches  from  theii 
eyes.  This  phenomenon  was  occasioned  by  tht, 
fall  of  an  enormous  quantity  of  volcanic  dust  issu- 
ing from  a  crater  on  the  Isle  of  St.  Yincent,  and 


242         METEORS   AND   METEORIC   PHENOMENA. 

containing,  according  to  the  analysis  made  by  Dr. 
Thompson,  ninety-one  parts  of  silex  and  alumi- 
num, eight  of  calcareous  matter,  and  one  of  oxide 
of  iron.  This  new  kind  of  rain,  and  the  profound 
darkness  it  occasioned,  did  not  cease  entirely  un- 
til between  noon  and  one  o'clock ;  but,  several 
times  during  the  morning,  there  were  noticed,  by 
the  aid  of  a  lantern,  showers,  so  to  speak,  in  which 
the  dust  fell  in  greater  abundance.  Trees  whose 
wood  was  flexible  bent  beneath  the  burden,  and 
the  noise  that  the  branches  of  other  trees  made 
in  breaking  contrasted  in  a  very  striking  manner 
with  the  calmness  of  the  atmosphere.  The  su- 
gar-canes were  completely  beaten  down,  and  the 
whole  island  was  covered  with  a  bed  of  greenish 
ashes  an  inch  in  depth." 

The  Isle  of  St.  Yincent  is  situated  about  one 
hundred  and  six  miles  to  the  west  of  Barba- 
does,  and  Arago  inferred,  from  the  passage  of  vol- 
canic ashes  to  such  a  distance,  that  there  is  an 
upper  current  blowing  in  a  direction  counter  to 
the  trade-winds,  which  in  these  regions,  and  par- 
ticularly during  the  months  of  April  and  May, 
blow  uniformly  from  the  eastward  with  a  slight  de- 
viation to  the  north.  We  must,  then,  admit  that 
the  volcano  on  St.  Yincent  had  hurled  the  immense 
quantity  of  ashes,  which  fell  upon  Barbadoes  and 


THE   DESERT    SANDS.  243 

the  adjacent  seas,  to  a  height  where  not  only  the 
trade-winds  ceased  to  be  felt,  but  even  where  a 
current  diametrically  the  reverse  of  them  pre- 
vailed. 

When  dispersed  by  the  winds,  volcanic  ashes 
sometimes  travel  very  great  distances.  Those 
that  issued  from  Vesuvius  were  found  at  Con- 
stantinople. In  the  formidable  eruption  of  Tom- 
boro,  a  volcano  of  the  island  of  Sumbawa,  which 
took  place  in  April,  1815,  the  ashes  went  as  far  as 
Java,  Macassar,  and  Batavia.  They  even  fell  at 
Bencoolen,  in  Sumatra,  more  than  nine  hundred 
and  thirty-one  miles  distant. 

THE   DESERT   SANDS. 

On  the  deserts,  the  winds  carry  great  masses 
of  sand,  which  sometimes  cause  terrible  catastro- 
phes. The  soil  is  composed  of  light  sand,  which 
the  storm  tosses  as  it  does  the  billows  of  the  sea. 
Enormous  whirlwinds  bury  whole  caravans,  and 
frequently  it  is  by  the  bones  found  in  the  sandy 
beds  that  the  way  across  these  vast  solitudes  is 
recognized. 

One  characteristic  feature  of  our  globe  is  the 
line  of  deserts  that  traverses  Africa  and'  Asia, 
forming  a  zone  of  four  hundred  leagues  in  diam- 
eter at  some  points,  with  a  total  length  of  nearly 


244         METEOES   AND   METEOKIO   PHENOMENA. 

three  thousand  leagues  from  the  Senegal  to  the 
Nile,  and  from  Arabia  to  Mongolia.  In  certain 
localities  of  Sahara,  and  in  the  Desert  of  Gobi,  the 
bottom  of  ancient  seas  has  been  distinctly  recog- 
nized ;  and  one  may  readily  conceive  of  an  epoch 
when  the  series  of  these  internal  sheets  of  water, 
the  Mediterranean,  the  Black  Sea,  the  Caspian, 
the  Aral,  and  all  the  lakes  of  the  steppes  as  far  as 
Lake  Baikal,  was  repeated  in  a  more  southern  but 
parallel  region  more  exposed  to  drought. 

"  This  prolongation  of  continuity  in  the 
deserts,"  says  Jean  Reynaud,  developing  this 
hypothesis,  "  might  be  very  readily  explained  by 
one  of  the  great  laws  of  the  atmosphere,  viz. :  the 
habitual  movement  of  the  air  from  west  to  east  in 
the  temperate  zones.  Supposing  separate  and 
distinct  aggregations  of  sand  to  have  existed 
originally,  and  to  have  been  arranged  like  the 
present  great  desert,  along  a  line  not  very  widely 
diverging  from  the  parallel  of  the  equator,  the 
sand  being  constantly  thrown  toward  the  east  by 
the  wind,  would,  at  length,  necessarily  have 
formed  along  the  whole  line,  commencing  at 
its  point  of  departure,  lengthened  sandy  trains 
joining  the  other  trains  behind  it,  and  thus  have 
united  all  the  primitive  deserts  in  one  single  waste. 
This  displacement  of  the  deserts,  this  continual 


THE   DESERT   SANDS.  245 

extension  of  their  limits  toward  the  east,  in  the 
temperate  zones,  at  least,  is  an  ascertained  fact. 
Nature  has  not  fixed  the  sand  as  she  has  the  sea. 
God  did  not  say  to  the  desert  when  He  created  it, 
'Thus  far  shalt  thou  go,  and  no  farther.'  It 
is  not  Egypt,  at  all  events,  that  would  contradict 
our  assertion.  The  wind  drives  the  sand  of  Sa- 
hara over  that  country,  and  has  already  scattered 
enough  upon  it  to  almost  entirely  cover  the  upper 
tracts  of  the  valley  of  the  Nile.  In  a  few  centuries 
more,  Upper  Egypt  will  be  completely  buried; 
the  sands  will  accumulate  at  the  foot  of  the 
mountains  that  separate  the  region  in  question 
from  the  Red  Sea,  until,  at  length  attaining  their 
level,  they  may  continue  their  onward  march,  and 
extend  over  AraBia  the  continuous  mantle  of  the 
desert. 

"  The  districts  of  the  Thebaid,  once  the  most 
densely-peopled  and  most  flourishing  on  earth, 
now  belong  to  the  sandy  waste.  The  temples 
rear  their  desolate  capitals  above  the  sand  as 
though  above  the  waters  of  a  deluge;  and  the 
sphinxes,  like  those  fossil  creatures  of  the  antedi- 
luvian world,  of  which  no  traces  are  now  discov- 
ered, excepting  in  the  bosom  of  the  subterranean 
strata,  repose  peacefully  in  its  depths." 

To  this  moving  picture  of  the  progressive  in- 


246         METEORS   AND   METEOKIO   PHENOMENA. 

vasion  of  the  deserts,  Jean  Reynaud  adds  the 
following  considerations:  "Will  the  trip  across 
these  inhospitable  solitudes  ever  become  more 
prompt  and  easy  than  it  is  now  ?  Has  the  indus- 
try of  civilized  nations  any  thing  to  add  to  what 
the  experience  of  the  nomadic  tribes  who  haunt 
the  desert,  has  invented  for  this  purpose  ?  In  my 
mind,  the  reply  to  this  question  is  n.ot  doubtful, 
so  great  does  the  scope  of  human  power  appear  to 
me ;  but,  at  the  same  time,  I  recognize  the  fact 
that  such  a  task  is  beyond  its  strength.  We  have 
subjected  the  ocean  by  means  of  steam,  we  may 
subdue  the  mountains  when  we  will  by  the  aid 
of  inclined  railroads,  but  how  shall  we  ever  make 
the  untamable  elements  of  the  desert  submit  ?  It 
is  a  rude  problem  to  solve.  Its  solution  assuredly 
cannot  be  directly  approached,  and,  besides,  the 
time  has  not  yet  come.  But  it  suffices  to  state 
the  question,  in  order  to  catch  a  glimpse,  at  once, 
of  the  full  majesty  of  the  desert.  A  force  which 
has  broken  down  so  many  other  barriers  has  not 
even  a  hold  on  this  one.  All  that  we  have  to  go 
upon,  in  attempting  to  speak  with  certainty  on 
this  subject,  for  the  honor  of  man,  is,  that  the  en- 
gineer now  knows  how  to  fix  and  confine  the  mov- 
ing sands  by  covering  their  edges  with  sufficient 
plantations  of  trees ;  that  the  agriculturist,  by  the 


THE   DESERT    SANDS.  24Y 

aid  of  irrigation,  succeeds  little  by  little  in  culti- 
vating and  fertilizing  the  most  arid  waste ;  and 
finally,  that,  in  countries  the  most  remote  from 
river-courses,  the  miner  can,  like  Moses  in  the 
desert,  by  striking  the  rocks  with  his  iron  rod, 
make  springs  leap  from  them,  and  thus  give  birth, 
in  plains  the  most  destitute  of  all  the  gifts  of  Na- 
ture, to  verdant  oases.  But  from  these  attempts, 
made  on  a  small  scale  in  some  districts,  to  the 
general  cultivation  of  Sahara,  and  to  the  establish- 
ment of  well-made  roads  across  a  grassy  surface, 
where  all  now  is  sand,  there  is  a  lapse  of  time  to 
come  as  prolonged  as  the  imagination  can  con- 
ceive." 

Let  us  here  add  that  the  recent  discovery  of 
an  immense  watery  deposit  extending  under  the 
Algerian  part  of  Sahara,  admits  the  hope  of  at 
least  a  slow  transformation.  At  every  spot  where 
the  subterranean  sheet  bursts  forth,  forests  of  palm- 
trees,  that  form  the  oases,  quickly  spring  up.  The 
oasis  of  Ouargla,  which  possesses  a  great  number 
of  Artesian  wells,  counts  as  many  as  one  hundred 
and  fifty  thousand  palm-trees,  that,  according  to 
the  Arab  saying,  live  with  "  their  feet  in  the 
water,  and  their  heads  in  the  fire."  These  still 
favor  the  cultivation  of  the  ground,  which  is  not 
possible  excepting  beneath  their  sheltering  shade. 


248         METEOKS   AND   METEORIC    PHENOMENA. 

£Tavigators>  in  following  the  coast  of  Africa, 
often  encounter  winds  to  which  their  burning 
heat,  an  extreme  dry  ness,  and  the  presence  of  sand, 
give  a  peculiar  character,  that  must  be  attributed 
to  their-  passing  over  the  desert.  These  winds  are 
designated  according  to  locality,  as  the  simoom, 
the  sirocco,  the  Jchamsin,  the  harmattan,  etc. 
Zhiring  the  continuance  of  the  simoom,  which 
often  blows  in  a  whirlwind,  a  temperature  of  fifty 
degrees  has  been  noted  in  the  shade.  The  sirocco 
reaches  the  coasts  of  Italy,  and  carries  the  sand 
along  with  it.  The  khamsin,  which  is  of  very 
elevated  temperaturej  owes  it  name,  meaning  fifty, 
to  its  long  duration.  It  precedes  and  follows  the 
equinox  for  twenty-five  days.  The  harmattan 
blows  upon  the  coast  of  Guinea,  and  is  always 
accompanied  by  a  peculiar  kind  of  fog.  "  This 
fog,"  says  Arago,  "  is  so  dense  as  to  afford  passage 
to  but  few  rays  of  the  sun  at  noonday,  and  al- 
ways rises  when  the  harmattan  is  blowing.  The 
particles  of  which  it  is  formed  deposit  themselves 
on  the  sod,  on  the  leaves  of  the  trees,  and  on  the 
skin  of  the  negroes,  in  such  fashion  that  every 
thing  for  the  time  being  looks  white.  The  na- 
ture of  these  particles  is  unknown.  All  that  we 
do  know  about  them  is,  that  the  wind  carries 
them  but  a  very  little  distance  out  upon  the  ocean 


THE  RED  FOGS  AT  CAPE  VERDE.       249 

away  from  the  coasts.  Only  one  league  at  sea 
the  fog  is  much  attenuated,  and  at  three  leagues 
there  is  not  a  trace  of  it  to  be  seen,  although  the 
harmatfcm  makes  itself  felt  there  in  full  force." 

THE   RED    FOGS    AT    CAPE   VERDE. 

M.  Ehrenberg  believes  that  the  name  of  dark 
or  gloomy  sea,  given  to  the  Atlantic  by  the  an- 
cients, took  its  rise  in  the  phenomenon  observed 
after  the  mariner  has  issued  forth  from  the  Straits 
of  Gibraltar  and  is  drawing  near  to  the  waters 
by  Cape  Yerde.  At  the  approach  of  the  equi- 
noxes, and  during  an  interval  that  varies  from 
thirty  to  forty  days,  there  falls  a  very  fine  red 
powder  that  obscures  the  atmosphere  and  deposits 
itself  upon  the  rigging  of  vessels.  This  shower 
of  dust,  known  also  as  the  red  fog,  extends  over  a 
sea-surface  of  more  than  a  million  of  square  miles. 

Showers  of  red  dust  have  been  frequently 
noted,  also,  at  different  points  on  the  Mediter- 
ranean, and  in  Europe  and  "Western  Asia,  but  at 
irregular  epochs.  Near  Lyons,  for  instance,  in 
1846,  there  fell  a  quantity,  estimated  in  all  at 
seven  thousand  two  hundred  quintals,  on  a  sur- 
face of  four  hundred  square  miles.  This  dust  is 
not  composed  of  sand  and  clay  alone,  but  also  of 
organic  substances  and  infusoria,  which  a  powerful 


250         METEORS    AND    METEORIC    PHENOMENA. 

microscope  renders  quite  visible.  A  sort  of  worm, 
which,  along  with  the  clay,  gives  color  to  the  mix- 
ture, is  so  small  that  it  requires  nearly  two  mill- 
ions of  these  animalcula  to  fill  the  space  of  a 
cubic  inch.  One  thing  especially  remarkable  is, 
that,  in  the  many  specimens  examined  by  M. 
Ehrenberg,  and  collected  on  the  Atlantic  as  well 
as  in  Europe,  Asia  Minor,  and  Syria,  the  same 
species  have  always  been  found.  The  savant  in 
question  has  prepared  a  chart  on  which  all  the 
places  where  this  dust  has  fallen  are  marked.  He 
admits  that  the  showers  of  blood  mentioned  in 
history  may  have  been  confounded  with  this  phe- 
nomenon, since  the  fluid  in  question  might  well 
be  represented  by  the  red  substance  above  men- 
tioned, when  the  latter  is  moistened  with  water, 
and  such  an  explanation  of  the  legendary  fact  is 
too  obvious  to  be  rejected. 

The  interesting  question  of  the  origin  of  these 
peculiar  kinds  of  dust  then  occupied  his  attention, 
and  led  him  to  analyze  a  great  many  specimens  of 
the  soil  collected  in  different  parts  of  Africa  and 
South  America.  The  result  showed  that  nowhere 
on  the  first-named  continent  could  species  of  in- 
fusoria be  found  the  same  as  those  discovered  in 
the  dust,  while  on  the  second  they  were  met  with 
near  the  Orinoco  and  Amazon  Rivers. 


THE   BED   FOGS    AT   CAPE   VERDE.  251 

This  circumstance  very  forcibly  struck  tlie  at- 
tention of  Commander  Maury,  who  saw  ,that  these 
dust-falls  may  serve  to  mark  the  extent  of  the  cir- 
cuit made  by  the  aerial  currents,  just  as  bottles 
thrown  into  the  sea  by  mariners  mark  the  sweep 
of  the  ocean-currents. 

The  periodicity  indicated  by  the  appearance 
of  this  dust  at  Cape  Verde  has  relation,  according 
to  Maury,  to  the  movement  of  oscillation  north 
and  south  of  the  zone  of  equatorial  calms,  a  move- 
ment that  carries  the  rainy  season  from  point  to 
point  over  the  surface  of  America.  "  At  the 
period  of  the  spring  equinox,"  he  says,  "  the  val- 
ley of  the  lower  Orinoco  is  in  its  dry  season ;  the 
marshes  and  plains  in  that  region  are  converted 
into  arid  deserts ;  the  water  has,  so  to  speak,  dis- 
appeared, and  the  trade-winds  can  very  readily 
bear  away  with  them  the  dust  that  whirls  about 
on  these  parched  savannas.  Six  months  later,  at 
the  autumnal  equinox,  the  relative  position  of  the 
zones  of  calm  and  of  the  trade-winds  has  changed. 
It  is  the  greater  part  of  the  valley  of  the  Amazon 
which  becomes  a  prey  to  drought  and  which  in  its 
turn  furnishes  to  the  heavy  breezes  of  that  period 
of  the  year  the  organic  dust  that  we  find  in  the 
other  hemisphere." 

Ilumboldt  gives  us  an  easy  comprehension  of 


252         METEORS   AND   METEORIC   PHENOMENA. 

how  the  dust  is  carried  up  from  those  burning 
plains :  "  When,  under  a  vertical  sun  and  a  cloud- 
less sky,  the  grassy  carpet  is  scorched  to  a  cinder 
and  reduced  to  dust,  the  baked  soil  cracks  open 
as  though  it  had  been  split  by  violent  shocks 
of  earthquake.  Should  opposite  currents  of  air 
meet  each  other  midway  at  this  moment,  and  by 
their  conflicting  action  produce  a  gyrating  move- 
ment, the  plain  presents  a  strange  spectacle  to 
the  observer.  The  sand  rises  like  a  conical  cloud, 
the  point  of  which  scores  the  ground,  in  the 
midst  of  the  whirlwind,  which  is  highly  charged 
with  electricity.  It  might  be  mistaken  for  one 
of  those  howling  tornadoes  so  dreaded  by  the 
experienced  seaman.  The  vault  of  the  heavens, 
which  seems  lower  down  than  usual,  reflects  only 
a  dull  and  opaline  light  over  the  plain.  Sudden- 
ly, the  horizon  seems  to  draw  closer  and  space 
contracts.  Suspended  in  the  cloudy  atmosphere, 
the  red,  hot  dust  still  augments  the  suffocating 
temperature  of  the  air;  and,  instead  of  refresh- 
ing coolness,  the  east  wind,  sweeping  over  the 
burning  soil,  only  brings  a  more  blazing  heat." 

SHOWERS    OF   MANURE. 

We  have  still  to  mention  certain  kinds  of  dust 
that  are  floating  continually  around  us,  and  which 


SHOWERS   OF   MANURE.  253 

the  luminous  ray  causes  to  appear  to  us,  in  any 
dark  space,  in  whirlwinds  of  sparkling  particles. 

There  mingle  in  the  dust  of  our  streets  and 
roads  some  detached  remains  of  every  thing  we 
use — the  tiny  atoms  of  the  smoke  that  rises  from 
our  hearths,  as  well  as  the  floating  molecules  that 
escape  in  the  decomposition  of  organic  bodies. 
These  materials  are  of  great  value,  as  learned 
agriculturalists  have  indicated.  "  Perhaps,"  says 
M.  Barral,  "it  would  be  correct  to  say,  that 
the  air  remaining  in  a  condition  of  purity  equal 
to  that  which  is  sometimes  attained  in  our  labo- 
ratories, would  strike  the  earth  with  barrenness. 
Perhaps,  too,  it  is  necessary  for  the  maintenance 
of  life  on  our  planet,  that  a  host  of  impurities 
should  be  incessantly  carried  hither  and  thither, 
by  the  winds  and  the  storms,  from  the  places 
where  they  are  produced  to  regions  where  germs 
are  waiting  to  be  fructified." 

A  great  number  of  salts  (for  instance,  marine 
salt),  that  are  adapted  to  the  provision  of  elements 
necessary  to  vegetation,  exist  in  rain-water,  and 
consequently  in  the  atmosphere.  Dalton  found 
one  hundred  and  thirty-seven  milligrammes  of 
chloride  of  sodium  (or  marine  salt)  per  litre  near 
Manchester,  and  M.  Barral  has  ascertained  that 
there  are  four  milligrammes  in  the  rain-water  of 


254         METEORS  AND  METEORIC   PHENOMENA. 

Paris.  As  we  retire  from  the  sea,  the  proportion 
of  salt  diminishes,  and  every  thing  leads  us  to 
infer  that  this  substance  is  raised  from  the  bil- 
lows of  the  ocean  by  the  great  winds,  and  borne  to- 
ward the  interior.  Salt-rains  are  often  mentioned 
in  works  on  meteorology,  and  Pliny  cites  several 
instances.  Sometimes  there  have  been  found, 
with  the  salt,  the  iodine  and  bromine  that  accom- 
pany it  in  the  brine  of  the  deep. 

Particles  of  phosphoric  matter  also  are  often 
detected  in  the  air.  They  have  been  carried  up, 
no  doubt,  in  the  form  of  dust,  from  those  parts 
of  the  globe's  surface  where  the  phosphate  of 
lime  is  abundant.  This  dust,  descending  along 
with  the  rain,  contributes  powerfully  to  the  fer- 
tility of  the  soil.  Each  crop  of  grain  withdraw- 
ing seventeen  and  a  half  pounds  of  phosphorus 
per  acre  from  the  soil,  and  the  supply  yielded  by 
the  atmosphere  being  much  less,  we  may  readily 
comprehend  why  races  who,  like  the  Arabs,  nev- 
er manure  their  lands,  are  obliged,  after  having 
drawn  some  scanty  products  from  them,  to  aban- 
don them  for  several  years,  until  the  soil  shall 
have  reacquired  the  elements  necessary  for  a  new 
crop.  The  sea,  which  in  certain  circumstances, 
and  particularly  during  tempests,  becomes  illu- 
minated with  the  phosphorescent  coruscations  due 


wmWrnaulIMOM 


DRY   FOGS.  255 

to  the  presence  of  innumerable  animacules,  must 
also  contribute  to  the  diffusion  of  phosphorus. 
This  substance  likewise  comes  from  the  subter- 
ranean putrefaction  of  animal  matter,  and  dis- 
perses itself  in  the  atmosphere,  above  swamps  and 
marshes,  by  means  of  those  mysterious  Jack-o'- 
lanterns,  or  Will-o'-the-wisps,  that  have  given  rise 
to  so  many  superstitious  stories. 

DRY    FOGS. 

We  mention,  along  with  atmospheric  dust,  the 
phenomena  known  as  dry  fogs,  due  to  matter  of 
great  tenuity,  but  not  aqueous,  suspended  in  the 
atmosphere,  the  clearness  of  which  they  overcloud. 
Humboldt,  when  on  the  summit  of  the  Silla,  found 
himself  enveloped  in  a  dense  cloud  that  concealed 
the  nearest  objects  from  his  view,  without  his 
clothing  being  dampened  in  the  least  degree.  At 
the  same  time,  the  hygrometer  marked  the  highest 
degree  of  dryness. 

In  Switzerland,  the  name  of  hale  is  given  to  a 
sort  of  smoke  that  accompanies  the  north  wind 
during  the  summer,  and  extends  around  the  hori- 
zon, shutting  out  the  Alps  from  view.  It  is  some- 
times gray,  sometimes  red  or  russet-colored,  and 
the  sun  when  seen  through  it  has  a  sombre,  red- 
dened hue.  The  callina  is  a  similar  exhalation 


256         METEORS    AND   METEORIC    PHENOMENA. 

in  Spain,  which  gives  the  sky  a  leaden  or  livid 
tinge. 

In  the  north  of  Germany,  certain  dry  fogs  are 
but  real  smoke  produced  in  the  fields  by  the 
combustion  of  turf  and  other  vegetable  matter. 
Broad  surfaces  sometimes  take  fire  spontaneously 
in  the  peat-bogs,  and  the  quantity  of  combustible 
material  consumed  often  amounts  to  millions  of 
pounds.  It  has  been  noted  that  the  wind  always 
blows  from  the  direction  of  the  turf-beds  when 
there  is  a  dry  fog.  "  The  dense  fog  of  1834 
came,"  says  Kaemtz, "  from  the  combustion  of  the 
peat-beds,  and  from  the  many  fires  that  marked 
the  year.  When  it  was  noticed  in  the  Hartz 
Mountains,  toward  the  end  of  May,  there  were 
fires  in  the  peat-beds  in  the  neighborhood  of 
Bdsle  and  Orleans.  Thus,  to  mention  one  par- 
ticular case,  the  peat-beds  of  Dachau,  in  Bavaria, 
burned  to  a  depth  of  more  than  nine  feet,  and  the 
fire  propagated  itself  beneath  ditches  full  of  water. 
In  the  environs  of  Minister,  and  in  Hanover,  many 
peat-beds  were  consumed.  Later,  in  July,  there 
were  terrible  conflagrations  in  the  forests  and 
turf-pits  near  Berlin,  in  Silesia,  in  Sweden,  and  in 
Russia,  and  the  drought  favored  the  propagation 
of  these  fires  and  the  drifting  of  the  smoke." 

M.  le  Yerrier  has  given  a  description  of  a 


DRY  FOGS.  257 

singular  cloud  which  is  noticed  daily  at  Paris. 
It  comes  from  the  smoke  of  the  forges  situated  in 
the  direction  of  the  Maison  Blanche :  "  The  spec- 
tacle," says  he,  "  is  really  curious  to  see.  From 
the  top  of  the  chimney  issues  a  cone  as  black  as 
ink.  This  cone  spreads  open,  little  by  little, 
gains  distance  over  the  city  of  Paris,  and  passes 
beyond  it,  sometimes  to  the  north  and  sometimes 
to  the  south  of  the  Observatory.  When  it  passes 
to  the  northward,  we  follow  it  with  our  gaze  as 
far  as  Gentilly.  No  sunshine  falls  at  that  mo- 
ment on  a  large  part  of  Paris.  At  least  such  is 
what  the  inhabitants  think;  the  sun  is  really 
hidden  by  the  smoke  of  these  forges,  while  to  the 
northward  it  is  brilliant." 

Sometimes  immense  swarms  of  insects  have 
presented  the  appearance  of  a  collection  of  clouds : 
"On  Tuesday,  the  7th  of  September,  in  very 
calm  weather,  workmen  employed  in  replanting 
a  part  of  the  Esperou  Mountain  witnessed  an  ex- 
traordinary phenomenon,  one  unexampled,  in  fact, 
in  those  regions.  At  two  o'clock  in  the  after- 
noon, a  dull  and  monotonous  noise,  almost  analo- 
gous to  that  produced  by  a  distant  thunder-storm, 
fixed  their  attention  upon  a  dense  mist  that  was 
sweeping  over  a  small  hill  about  six  miles  in  ad- 
vance of  them.  As  the  air  was  very  calm,  they 


258         METEORS    AND   METEORIC    PHENOMENA. 

were  astonished  at  this  humming  sound,  and  their 
first  idea  was  of  a  fire  in  the  direction  of  Esperou ; 
but,  determined  to  ascertain  the  real  reason  of  so 
intense  a  mist,  they  were  no  little  surprised  when, 
as  they  moved  toward  it,  they  discovered  that  it 
was  an  immense  column  of  gnats,  the  length  of 
the  cloud  being  some  five  thousand  feet,  with  a 
perpendicular  depth  of  from  one  hundred  to  two 
hundred  feet.  This  column  of  insects  was  mov- 
ing from  east  to  west.  An  eye-witness,  a  forest- 
keeper  who  was  superintending  the  workmen  in 
the  woodland,  has  furnished  us  these  particulars." 
An  extraordinary  dry  fog  extended,  in  1783, 
over  the  whole  surface  of  Europe,  and  a  part  of 
Asia.  Its  density  was  such  that,  in  some  places, 
objects  less  than  a  mile  distant  could  not  be  dis- 
guished,  and  people  could  look  at  the  noonday 
sun  without  being  dazzled.  This  phenomenon 
was  first  remarked  at  Copenhagen  on  the  9th  of 
May,  after  a  succession  of  fine  days.  At  other 
places  it  was  preceded  by  wind  and  rain.  It 
was  seen,  on  the  6th  of  June,  at  La  Rochelle ;  at 
Dijon  on  the  14th,  and  on  the  16th  at  Manheim 
and  at  Eome.  It  appeared  on  the  19th  in  the 
Netherlands ;  on  the  22d,  in  Norway ;  on  the 
23d,  on  the  Saint  Gothard  and  in  Hungary ;  tow- 
ard the  close  of  June,  in  Syria ;  and  by  the  1st  of 


DRY   FOGS.  259 

July  on  the  tops  of  the  Altai  Mountains.  Its  du- 
ration varied  at  different  places ;  and  it  was  inter- 
rupted, here  and  there,  by  fine  days.  This  fog 
had  one  remarkable  peculiarity  during  the  night- 
time :  it  was  phosphorescent,  and  the  light  it 
yielded  was  sufficient  to  read  by. 

A  great  many  conjectures  have  been  offered 
as  to  the  cause  of  this  phenomenon.  Yan  Swin- 
den  and  Toaldo  think  it  attributable  to  the  earth- 
quakes and  volcanic  eruptions  which  in  that  same 
year  disturbed  Calabria  and  Iceland.  From  the 
month  of  February  until  the  end  of  March,  there 
were  terrible  commotions  of  the  earth's  surface  in 
Calabria ;  mountains  were  shattered,  an  immense 
number  of  chasms  opened  and  emitted  smoke,  and 
more  than  one  hundred  thousand  human  beings 
perished  under  the  ruins  of  the  fallen  cities. 

The  eruptions  commenced  in  Iceland  on  the 
1st  of  June.  Seventeen  villages  were  swallowed 
up,  and  the  lava  of  Hecla  consumed  a  great 
quantity  of  vegetable  matter.  There  were  also 
many  turf-beds  in  combustion  throughout  Europe. 
But  none  of  these  explanations  sufficed.  Frank- 
lin, at  last,  put  forward  an  hypothesis  that  prob- 
ably comes  near  to  the  truth.  According  to  his 
idea,  an  immense  fiery  meteor  had  been  burning 
in  the  upper  regions  of  the  atmosphere,  and 
13 


260         METEORS  AND   METEORIC   PHENOMENA. 

the  strange  fog  was  due  to  a  vapor  of  cosmic 
origin. 

A  similar  phenomenon  was  observed  in  the 
month  of  August,  1831,  in  a  part  of  Europe,  upon 
the  north  coast  of  Africa,  and  in  the  United 
States.  It  diminished  the  light  of  day,  and,  in 
the  night-time,  diffused  a  phosphorescent  radi- 
ance. No  comet  having  been  discovered  at  the 
epochs  when  these  dry  mists  appeared,  they  could 
not  be  considered  the  product  of  the  cometary 
vapors  that  the  earth,  according  to  Arago,  has  to 
traverse  several  times  in  the  course  of  a  century, 
and  which  must  be  the  origin  of  the  atmospheric 
phenomena  that  are  sometimes  visible,  but  more 
frequently  pass  unperceived,  owing  to  the  exces- 
sive tenuity  of  the  matter  that  composes  the  tails 
of  comets. 


OHAPTEE  XL 

PROGNOSTICS   OF  THE   WEATHER. 

Progress  of  Meteorology.  —  Foretelling  the  Weather.  —  Orpheus,  Ho- 
mer, Hesiod,  Virgil.— Prognostics  furnished  by  Animals.— Prognos- 
tics from  Plants,  and  from  the  State  of  the  Sky.— Characters  of  the 
Seasons  and  of  Future  Years.— Shooting-Stars.— Influence  of  the 
Moon. 

THE  PROGRESS  OF  METEOROLOGY. 

HIPPOCRATES,  in  his  "Treatise  on  Atmos- 
pheres, Waters,  and  Places,"  and  Aristotle,  in  his 
"Meteorologies,"  submitted  the  observation  of 
atmospheric  phenomena  to  experimental  meth- 
ods, and  collated  the  first  elements  of  a  positive 
meteorology.  The  progress  of  science,  notwith- 
standing the  living  impulse  given  by  these  two 
great  minds,  and  in  spite  of  the  labors  of  The- 
ophrastus,  Pliny,  and  Seneca,  was  very  slow  un- 
til the  middle  ages,  when  the  discoveries  of  Avi- 
cenna,  of  Albert  le  Grand,  and  Eoger  Bacon, 
caused  it  to  take  a  new  step  in  advance.  But  it 
is  to  the  remarkable  progress  of  the  physical 


262         METEORS   AND   METEORIC    PHENOMENA. 

sciences,  to  Galileo,  Porta,  Descartes,  Pascal, 
Huygens,  and  Mariotte,  that  meteorology  owes 
the  discoveries  that  have  secured  its  development. 

Among  the  learned  men  whose  labors  have, 
more  recently,  given  a  powerful  flight  to  this 
most  important  branch  of  science,  we  may  mention 
Humboldt  and  Maury,  to  whom  we  are  indebted 
for  the  increased  number  of  observations  which, 
on  land  and  sea,  are  now  gathering  so  much  pre- 
cious information.  It  is  also  to  their  persever- 
ing initiative  that  we  owe  the  large  developments 
through  which  meteorology  is  now  entering  the 
path  of  practical  usefulness,  and,  by  its  numer- 
ous applications  to  agriculture,  navigation,  public 
health,  geology,  etc.,  enhancing  the  universal  in- 
terest its  researches  have  always  awakened. 

If  we  bring  together  the  superstitious  notions 
of  the  past,  and  the  teachings  of  contemporane- 
ous science,  we  see  that  it  is  to  the  love  of  the 
marvellous,  to  our  common  predilection  for  the 
unknown,  as  much  as  to  our  primitive  ignorance, 
that  we  must  attribute  the  appeal  to  the  super- 
natural made  by  the  ancients  upon  nearly  all 
occasions  when  they  tried  to  account  for  atmos- 
pheric and  terrestrial  phenomena.  But  this  ten- 
dency, which,  even  through  so  many  errors,  has 
after  all  guided  us  toward  the  truth,  still  exists  in 


THE  PROGRESS  OF  METEOROLOGY.      263 

us,  and  we  must  reflect  that  it  will  never  cease  to 
intervene  in  our  moral  and  intellectual  progress. 
Directed,  in  our  day,  toward  regions  less  obscure, 
toward  truths  more  luminous  and  imposing,  it 
will  lead  us  to  a  higher  interpretation  of  Divine 
management,  and  a  more  exact  recognition  of  the 
fundamental  laws  the  sway  of  which  beneficently 
maintains  "  order  in  the  universe  and  magnifi- 
cence in  order,"  as  Humboldt  has  grandly  said  in 
his  "  Cosmos." 

Notwithstanding  the  favorable  direction  im- 
parted to  meteorology  by  the  labors  of  several  cel- 
ebrated savants,  this  science  is  still  far  from  ap- 
proaching the  perfection  of  the  other  natural 
sciences.  It  is  made  up  of  multiple  and  variable 
phenomena,  which  are  further  complicated  by  a 
host  of  circumstances,  from  the  influence  of  which 
it  is  impossible  to  separate  them,  and  which  are 
modified  to  an  endless  extent  by  climate,  local  ar- 
rangement, the  configuration  of  places  and  sites, 
and  the  nature,  the  elevation,  or  the  depression 
of  the  soil.  Thus,  it  is  only  by  multiplying  our 
observations,  by  repeating  them  incessantly  in 
different  places,  that  we  can  reach  the  point  where 
we  can  shape  them  into  general  laws,  of  which 
we  may  catch  a  glimpse  in  the  general  totality 
of  the  phenomena,  but  whose  application  escapes 


264:         METEOK8   AND   METEOEIO   PHENOMENA. 

us  under  particular  circumstances.  Should  we 
ever  succeed  in  reducing  the  phenomena  of  meteor- 
ology to  a  small  number  of  fundamental  laws,  we 
may,  perhaps,  some  day  get  far  enough  on  to  fore- 
tell the  intensity  of  the  seasons  with  a  certain  de- 
gree of  probability.  "Without  mentioning  all  the 
advantages  that  would  result  from  this,  who,  we 
may  ask,  would  question  the  importance  of  in- 
formation that  would  direct  the  cultivator  how 
to  combine  his  operations  in  accordance  with 
the  weather  that  would  favor  or  retard  them  ? 
But  man  is  far  from  having  attained  such  a  de- 
gree of  perfection  as  this.  Nevertheless,  we  should 
not  despair  of  yet  accomplishing  it.  Who  will 
venture  to  lay  down  limits  to  science  ?  The  hu- 
man mind  has  already  unveiled  enough  of  Nature's 
secrets  to  let  us  hope  that  we  may  surprise  a  few 
more  of  them. 

This  correct  appreciation  of  the  services  that 
meteorology  is  called  upon  to  render,  and  of  the  ne- 
cessity of  the  numerous  observations  which  alone 
can  give  it  a  secure  foundation,  points  out  at  once 
the  end  to  be  reached,  and  the  means  of  reaching 
it.  But  while,  for  most  of  the  other  sciences,  the 
observations  to  be  collected  are  nearly  always 
either  beyond  our  reach,  or  surrounded  by  diffi- 
culties that  confine  them  within  the  circle  of  a 


HOMER,    HESIOD,    VIRGIL.  265 

few  learned  men,  in  meteorology,  on  the  con- 
trary, any  one  may,  by  bringing  to  bear  a  little 
perseverance,  acquire  knowledge  enough  to  recog- 
nize the  weather-signs  to  a  useful  degree. 

ORPHEUS,    HOMEK,    HESIOD,    VIRGIL. 

From  the  first,  man  has  found  himself  sub- 
jected, either  directly  or  indirectly,  to  the  influ- 
ence of  atmospheric  phenomena.  Exposed  to  the 
inclemencies  of  the  weather,  he  not  merely  had  to 
seek  shelter  in  a  substantial  dwelling,  but  to  direct 
his  attention  to  the  work  of  discovering  before- 
hand the  perturbations  that  he  might  subsequently 
have  to  endure. 

The  connection  between  these  disturbances  of 
the  air,  the  variableness  of  the  seasons,  and  the 
production  of  the  fruits  of  the  earth,  was,  more- 
over, narrowly  bound  up  with  his  material  well- 
being  ;  and  we  can  readily  understand  the  grati- 
tude of  the  original  tribes  toward  those  men  whose 
intelligence,  loftier,  more  active,  more  patient,  and 
more  enlightened,  than  their  own,  was  enabled  to 
seize  the  link  between  certain  phenomena  and 
the  appearance  of  premonitory  signs.  The  first 
priests,  the  first  legislators,  were  also  in  the  days 
of  antiquity  the  first  meteorologists.  "We  find 
traces  of  their  teachings,  mingled  with  the  stran- 


266         METEORS  AND   METEORIC   PHENOMENA. 

gest  superstitions,  in  the  primitive  fragments  at- 
tributed to  Orpheus,  in  the  poems  of  Homer,  He- 
siod,  and  Yirgil. 

Two  hymns  of  Orpheus  invoke  the  favoring 
breezes  and  the  beneficent  rains  that  fertilize  the 
soil: 

THE   CLOUDS. 

"  Aerial  clouds,  O  wanderers  of  heaven,  gen- 
erators of  all  the  fruits !  ye  who  hold  in  your 
bosoms  the  treasures  of  the  rain ;  ye  who  trav- 
erse the  world,  driven  by  the  breath  of  the  winds ; 
thunder-striking,  naming,  reechoing  clouds,  that, 
turn  by  turn,  spread  through  the  air  a  gentle  mur- 
mur or  the  howl  of  tempests,  I  now  implore  ye  to 
pour  out  upon  the  earth  the  favoring  rains  that 
fructify  the  buds  and  germs  ! " 

THE   SEASONS. 

"  Seasons,  darling  daughters  of  Jove  and  of 
Themis,  the  most  fruitful  goddess  of  all !  ye  who 
load  us  with  benefits,  O  richly  verdant,  blossom- 
ing, pure,  delicious  seasons — seasons  with  varied 
mingling  colors,  shedding  abroad  a  fragrant  breath 
— ever-changing  seasons,  accept  our  pious  offerings, 
and  send  us  the  aid  of  the  favoring  winds  that 
make  the  harvests  ripen !  " 

Homer,  in  the  "  Odyssey,"  and  Hesiod,  in  his 


THE  SEASONS.  267 

"  Works  and  Days,"  point  out  the  first  meteorolo- 
gical observations  of  seamen  and  farmers,  the  pe- 
riods of  each  season  that  should  be  preferred,  in 
order  to  conduct  the  tillage  of  the  ground  or  avoid 
the  dangers  of  navigation  with  success.  These 
periods  correspond  with  the  courses  of  the  stars, 
and  of  the  principal  constellations,  Arcturus,  the 
Pleiades,  Orion,  and  Sirius,  which  alternately  rise 
and  disappear,  marking  the  advance  of  the  seasons 
in  the  starry  heavens.  Thus  the  "  moist  Pleiades," 
which,  toward  autumn,  reascend  our  horizon  at 
the  beginning  of  night,  announce  the  return  of  the 
rains.  Arcturus,  which  brings  back  "  spring  with 
its  white  flowers,"  rises  in  April  and  presides  over 
the  first  labors  of  the  new  season.  Orion  and 
Sirius  light  up  the  stormy  skies  of  the  long 
nights  in  winter,  when  the  frost  strips  the  fields, 
and  when  the  unchained  tempests  detain  the  mar- 
iner in  port. 

Yirgil,  who  has  summed  up  in  his  "  Georgics" 
the  whole  meteorological  science  of  his  epoch, 
thus  recommends  the  indications  deduced  from 
the  movements  of  the  stars : 

"  The  field  laborer  should  notice  the  rising  of 
the  Bear,  the  Kids,  and  the  luminous  Dragon,  with 
the  same  care  the  skilful  pilot  shows  when,  in  order 
to  return  to  his  country  across  the  stormy  seas,  he 


268         METEORS   AND   METEORIC   PHENOMENA. 

has  to  face  the  Hellespont  or  the  perilous  Strait  of 
Abydos." 

But  to  these  elementary  indications  are  added 
others  more  important,  presented  by  observation 
of  the  signs  by  which  "  we  learn  to  read  a  doubt- 
ful sky."  The  course  of  the  moon  and  the  sun, 
their  different  aspects,  the  form  and  color  of  the 
clouds,  the  appearance  of  meteors,  the  instinctive 
movement  of  animals,  are  connected  with  the 
changes  of  the  weather,  which  we  may  foresee 
by  an  attentive  study  of  the  sky  and  the  atmos- 
phere. It  is,  moreover,  evident,  and  Yirgil  well 
understood  the  fact,  that  this  study  required,  in 
order  to  yield  all  its  fruits,  a  series  of  different 
classes  of  knowledge,  hardly  dreamed  of  by  an- 
tiquity : .  .  .  "  Let  the  Muses  deign  to  admit  me 
into  their  holy  choirs  !  Let  them  teach  me  the 
track  that  is  followed  by  the  heavenly  bodies; 
what  cause  now  eclipses  the  light  of  the  sun,  and 
now  the  light  of  the  moon  ;  what  secret  power  all 
at  once  swells  the  waters  of  the  sea,  pushes  them 
beyond  their  limits,  and  then  hurls  them  back 
upon  themselves ;  why  the  earth  shakes  on  its 
foundations  ;  why  the  sun  seems  to  hasten  in 
winter  to  quench  its  fires  in  the  ocean ;  and 
what  obstacle,  in  summer,  retards  the  approach 
of  night." 


THE   SEASONS.  269 

If  the  inaccurate  observation  of  natural  phe- 
nomena led  to  erroneous  or  superstitious  notions 
concerning  the  nature  and  the  formation  of  me- 
teors, it  cannot  be  denied  that  this  observation 
was,  likewise,  the  basis  of  the  knowledge  that  ad- 
vanced the  progress  of  meteorology,  and  which, 
spreading  and  growing  more  complete  from  age 
to  age,  destroyed  or  modified  the  ideas  of  the  past, 
in  order  to  substitute  more  rational  ideas  for  them. 
"  Necessary  as  it  is,"  said  Cicero,  "  to  extend  and 
confirm  religion  by  the  knowledge  of  Nature,  it  is 
equally  so  to  uproot  superstition." 

This  correct  and  sensible  view  of  the  case, 
which  applies  to  all  discoveries,  to  all  the  con- 
quests of  science,  has  an  especial  application  to 
meteorology,  whose  errors,  mingled  with  those  of 
astrology  and  alchemy,  have  so  long  veiled  the 
providential  order  of  things  that  lies  concealed 
under  the  apparent  confusion  of  these  phenom- 
ena. 

A  summing  up  of  the  errors  in  question,  which 
were  inseparable  from  the  first  researches  that  led 
us  to  the  truth,  might  have  some  interest  for  the 
reader,  but  it  would  carry  us  too  far,  and  we  pre- 
fer to  point  out  the  actual  condition  of  the  Mete- 
orognosy,  "  which  seeks  to  deduce  future  phenom- 
ena from  the  observation  of  phenomena  past  and 


270         METEORS    AND   METEORIC    PHENOMENA. 

present."  We  borrow  this  definition  from  the  ex- 
cellent treatise  of  M.  de  Gasparin  upon  agricul- 
tural meteorology,  which  is  about  to  serve  us  as  a 
guide,  as  we  shall  reproduce  a  few  passages  from 
it,  completing  them,  at  the  same  time,  by  a  con- 
cise statement  of  the  observations  most  recently 
made. 

METEOROLOGICAL   PROGNOSTICATIONS   FURNISHED   BY 
THE  ANIMALS. 

"Animated  bodies  receive  peculiar  impres- 
sions that  precede  and  announce  change  of 
weather.  Animals  appear  to  be  endowed  with 
an  instinct  in  this  respect,  by  which  observers 
have  profited,  and  man  himself,  when  perfectly 
healthy,  experiences  sensations  that  enable  him  to 
predict,  almost  with  certainty,  the  meteorological 
changes  that  are  about  to  ensue. 

"Thus,  we  hear  distant  sounds  better  when 
there  is  going  to  be  rain ;  we  also  then  see  re- 
mote objects  more  distinctly,  and  bad  odors  are 
more  offensive  than  usual. 

"  Swallows  skim  the  ground  in  their  flight ;  is 
it  that  they  may  feed  on  the  worms  that  then 
come  out  to  the  surface?  Lizards  hide,  cats 
make  their  toilet,  birds  oil  their  feathers,  flies  bite 
more  sharply,  chickens  scratch  themselves  and 


PROGNOSTICS   FROM  PLANTS.  271 

roll  in  the  dust,  fish  leap  out  of  the  water,  and 
aquatic  birds  flap  their  wings  and  dabble  in  the 
ponds  and  brooks.  Such  are  the  results  of  popu- 
lar observation.  They  have  not  been  subjected  to 
any  severe  criticism,  but  they  have  been  verified 
often  enough  to  be  no  longer  subjected  to 
doubt." 

PROGNOSTICS    FROM    PLANTS. 

"Nearly  all  the  signs  indicated  announce 
dampness  in  the  air,  rather  than  the  approach  of 
rain,  for  they  are  not  seen  when  a  storm  occurs  in 
dry  weather.  Thus,  the  swelling  of  wood-work, 
which  renders  it  difficult  to  close  doors  made  of 
soft  timber,  and  the  contraction  and  tension  of 
cordage  made  of  vegetable  fibres,  are  counted 
among  the  signs  of  atmospheric  humidity.  Rude 
hygrometers  have  even  been  constructed  of  these 
fibres.  It  has  been  noticed,  also,  that  the  flower 
of  the  pimpernel,  and  the  stems  of  the  trefoil  and 
other  plants,  straighten  themselves  when  the  air  is 
charged  with  moisture.  Linnaeus  remarked  that 
the  African  marigold  opened  its  flowers  between 
six  and  seven  in  the  morning,  and  shut  them  at 
four  o'clock  in  the  afternoon,  in  dry  weather, 
but  that,  if  rain  was  coming,  it  did  not  open  at 
all  in  the  morning ;  that,  when  the  Siberian  this- 


2Y2         METEOKS  AND   METEORIC   PHENOMENA. 

tie  shuts  its  flower  during  the  night,  there  is  good 
weather  on  the  next  day,  and  that  if,  on  the  con- 
trary, it  remains  open,  rain  may  be  expected." 

PROGNOSTICS    FROM   THE    STATE   OF   THE    SKY. 

"  Pallor  of  the  sun  announces  rain ;  it  is  seen, 
at  such  times  only,  through  an  atmosphere  laden 
with  vapors ;  if  the  heat  be  stifling,  that  too  is 
a  sign  of  rain,  for  one  is  then  surrounded  by 
an  atmosphere  saturated  with  vapors,  and  more 
readily  heated,  owing  to  its  lack  of  transparency. 
If  the  vapors  be  collected  in  clouds,  the  sun's 
rays  that  pass  through  the  latter  heighten  the 
temperature  more  than  they  would  have  done  in 
perfectly  clear  weather.  If  the  sun  be  clear  and 
brilliant,  it  foretells  a  fine  day ;  but,  when  the 
sun  is  at  its  rising  preceded  by  redness,  and  this 
redness  passes  off  the  moment  it  does  appear,  the 
sign  is  of  rain.  The  presumption,  then,  is,  that 
the  cold  and  vapor-laden  air  refracts  the  rays  of 
the  sun — a  power  that  it  loses  as  it  grows  heated 
by  the  rarefaction  of  those  same  vapors.  The  sun 
setting  clear  and  cloudless  in  an  orange-hued  sky, 
is  a  sign  of  fine  weather ;  if  the  sky  be  red,  it  is 
a  sign  of  wind. 

"When  the  sun  at  the  horizon  looks  larger 
than  usual,  the  sign  is  of  rain;  the  same  rule 


PROGNOSTICS  FEOM  THE  STATE  OF  THE  SKY.   273 

holds  good  in  reference  to  the  moon.  The  idea 
is,  also,  that — when  the  latter  orb  is  pale,  or  has 
concentric  circles  more  or  less  dark  around  her 
disk ;  when  her  horns  are  dull  at  the  ends ;  when 
a  luminous  halo  surrounds  her,  leading  to  the  ex- 
pression often  heard  among  the  people  in  France 
that  the  moon  is  bathing — there  is  going  to  be 
rain.  The  stars  also  offer  similar  signs;  their 
light  loses  all  its  vividness,  and  they  fiathe  when 
rain  is  at  hand. 

"The  sky  is  bluest  when  there  is  the  least 
vapor  between  it  and  the  eye  of  the  spectator. 
Upon  the  mountains  it  assumes  the  color  of  deep 
indigo.  "When  the  atmosphere  becomes  charged 
with  vapors,  it  loses  its  transparency,  and  the  hue 
of  the  sky  becomes  white,  or  floury,  as  the  saying 
is.  This  sign  is  unequivocal.  The  air  ceases  to  be 
transparent,  also,  through  the  effect  of  the  winds, 
which  agitate  and  carry  along  with  them  such  a 
quantity  of  dust  that  the  sky  sometimes  looks 
reddish  with  it,  owing  to  the  reflection  of  the 
light  upon  these  solid  corpuscles. 

"  The  transparency  of  the  air  is  not,  however, 
always  changed  by  the  approach  of  rain.  We 
have  even  mentioned  the  fact  that  one  of  the 
surest  signs  of  its  coming  is  an  unusual  transpar- 
ent clearness,  which  makes  distant  objects  seem  to 


274         METEORS   AND   METEORIC   PHENOMENA. 

draw  closer  at  such  times.  Thus,  in  one  case, 
the  lack  of  transparency  in  the  air,  and  in  the 
other  its  excess,  would  both  be  signs  premonitory 
of  rain.  Facts  agree  with  these  two  premises. 
Let  us  examine  the  circumstances : 

"  1.  If  the  entire  mass  of  air  be  very  damp, 
and  at  a  temperature  sufficiently  elevated  to  have 
completely  dissolved  the  vapor;  and  if,  at  the 
same  time,  we  suppose  the  heat  to  be  divided  be- 
tween its  strata  so  that  they  remain  in  equilib- 
rium, there  is  no  ascending  current  to  diminish 
the  transparency  of  the  air  by  cooling  as  it  as- 
cends, and  yet  all  the  circumstances  that  can 
change  the  temperature — the  diminution  of  heat 
as  the  sun  declines,  nocturnal  radiation,  and  the 
arrival  of  a  cold  wind — lead  to  rain.  This  con- 
dition of  equilibrium  in  the  strata,  joined  to  their 
almost  complete  saturation  with  vapor,  is  noticed 
particularly  in  summer,  and  it  is  then  that  dis- 
tant objects  seem  near  at  hand. 

"  2.  It  also  happens  that  the  higher  range  of 
clouds  will  sometimes  form  a  sort  of  dome  above 
our  heads,  and  then,  since  we  are  in  comparative 
obscurity,  the  objects  that  are  lighted  up  seem 
nearer  to  us.  We  recall  with  pleasure  the  superb 
spectacle  that  such  an  arrangement  of  the  sky 
presented  to  us  on  the  summit  of  Mont  Yentoux. 


PROGNOSTICS   FROM  THE   STATE   OF  THE  SKY.  275 

The  entire  horizon  was  clear,  but  the  mountain 
was  capped  with  a  heavy  mass  of  black  clouds, 
which  threw  us  into  gloom.  "We  were  then  ena- 
bled to  witness  something  that  we  never  could 
see  again  in  other  ascensions  that  we  made — the 
entire  sweep  of  the  eastern  Pyrenees  and  the 
coasts  of  the  Mediterranean  to  where  they  turn 
southward  to  regain  Catalonia.  A  moment  after- 
ward, a  cloud  overspread  the  sky  and  a  heavy 
rain  fell  over  that  whole  region,  the  atmosphere 
of  which  was,  no  doubt,  in  the  state  of  equilibrium 
that  we  have  described  above. 

"  The  winds  also  are  indications  of  the  weather 
to  ensue,  not  only  through  their  own  qualities, 
but  also  by  means  of  the  study  of  the  higher 
winds,  whose  presence  and  direction  are  known 
by  the  movement  of  the  clouds.  When  the  lower 
wind  strengthens  greatly,  and  the  clouds  move  in 
contrary  directions,  on  lines  that  make  a  quite 
open  angle,  the  inference  is,  that  the  lower  wind 
is  about  to  yield  its  place  to  the  upper  one. 

"  Two  winds  of  opposite  qualities,  succeeding 
each  other,  often  bring  rain.  Thus,  a  cold  wind, 
entering  an  atmosphere  impregnated  with  moist- 
ure by  the  warm  wind  that  preceded  it,  will  bring 
about  a  precipitation  of  water ;  and  the  same  will 
be  the  case  where  a  damp,  warm  wind  enters  air 


276         METEORS   AND   METEOEIC   PHENOMENA. 

that  had  been  chilled  by  the  wind  that  had  pre- 
ceded it. 

"  Generally,  an  approaching  rain  can  be  better 
foreseen  when  the  sky  presents  several  banks,  or 
layers  of  clouds,  resting  one  above  the  other.  The 
winds  that  carry  with  them  detached  masses  of 
clouds  yield  but  light  rains. 

"  Motionless  clouds,  lying  in  the  quarter 
whence  the  wind  blows,  bring  only  a  continuance 
of  that  wind ;  but,  if  they  appear  in  the  opposite 
quarter,  they  announce  its  termination. 

"Clouds  coming  up  simultaneously,  yet  im- 
pelled by  different  winds,  announce  an  early 
storm. 

"  Clouds  accumulating  on  the  sides  of  moun- 
tains foretell  rain. 

"  Mists  that  disperse  completely,  without  form- 
ing clouds,  accompany  fine  weather,  because  they 
prove  that  the  air  retains  the  faculty  of  dissolving 
vapor ;  but  many  days  of  mist  in  succession  lead 
almost  with  certainty  to  rain." 

Let  us  add  to  these  signs  a  few  collected  by 
Admiral  Fitzroy,  and  quoted  in  his  "  Instructions 
on  the  Use  of  the  Barometer." 

"  The  following  are  the  signs  most  familiar  to 
navigators  and  farmers : 

"  A  rosy  sky  at  sunset,  fine  weather.     A  red 


PROGNOSTICS   FROM  THE  STATE  OF  THE  SKY.    277 

sky  in  the  morning,  bad  weather  or  a  great  deal 
of  wind. 

"A  gray  sky  in  the  morning,  fine  weather. 
If  the  first  light  of  dawn  appear  over  a  bed  of 
clouds,  wind  may  be  looked  for.  If  on  the  hori- 
zon, fine  weather. 

"  Light  clouds  with  imperfectly-defined  edges 
announce  fine  weather  and  moderate  breezes. 
Thick  clouds  with  well-marked  edges,  wind.  A 
deep,  dark-blue  sky  of  sombre  tinge  indicates 
wind.  A  clear  and  brilliant-blue  sky  indicates 
fine  weather.  The  lighter  the  clouds  look,  the 
less  reason  is  there  to  anticipate  wind.  The  more 
dense,  the  more  rolled  together,  twisted,  and  tat- 
tered, they  are,  the  stronger  the  wind  will  be.  A 
brilliant-yellow  sky  at  sunset  announces  wind ;  a 
pale-yellow  one,  rain.  According  to  the  predom- 
inance of  red,  yellow,  or  grayish  tints,  we  can  fore- 
tell the  condition  of  the  weather  with  a  very  close 
approximation  to  accuracy. 

"  Small  clouds  of  an  inky  color  portend  rain. 
Light  clouds,  moving  rapidly  in  the  direction  op- 
posite to  dense  masses,  announce  wind  and  rain. 

"  High  clouds  passing  before  the  sun,  the  moon, 
or  the  stars,  in  a  direction  opposite  to  that  pursued 
by  the  lower  beds  of  clouds,  or  of  the  wind  felt  at 
the  surface  of  the  soil,  indicate  a  change  of  wind. 


278         METEORS  AND   METEORIC   PHENOMENA. 

"  After  fine  weather,  the  first  signs  of  a  change 
are  ordinarily  high  white  clouds,  in  belts  or  in 
light  dappled  tufts,  or  locks,  which  grow  larger, 
and  soon  form  dense  and  sombre  masses.  Gener- 
ally, the  more  remote  and  higher  up  these  clouds 
appear,  the  less  abrupt  the  change  of  weather  will 
be,  but  it  will  be  considerable. 

"  Soft,  light,  delicate  tints,  with  clouds  of  de- 
cided shape,  indicate  or  accompany  fine  weather. 
Extraordinary  tints  and  dense  clouds,  with  hard 
outlines,  indicate  rain  and  probably  a  gale  of 
wind. 

"  Remark  the  clouds  that  form  on  hills  and 
other  elevated  places,  and  cling  there.  If  they 
continue  there,  augment,  or  descend,  they  indicate 
rain.  If  they,  however,  ascend  and  disperse,  they 
portend  good  weather.  When  sea-birds  fly  out 
away  from  land  in  the  morning,  there  will  be  fine 
weather  and  moderate  winds.  If  they  remain 
near  the  shore,  or  fly  inland,  gales  and  storms 
may  be  expected.  Many  other  animals  are  suscep- 
tible to  atmospheric  changes,  and  these  indica- 
tions should  not  be  neglected. 

"  Thus,  when  birds  that  usually  fly  in  flocks, 
swallows  for  instance,  keep  near  to  their  nests,  fly- 
ing from  one  side  to  the  other  and  skimming  the 
ground,  the  sign  is  of  rain  or  wind.  When  do- 


PROGNOSTICS  FROM  THE  STATE   OF  THE  SKY.    279 

mestic  animals  seek  sheltered  places,  when  chim- 
neys smoke,  or  when,  in  calm  weather,  the  smoke 
does  not  ascend  overhead,  bad  weather  may  be 
expected. 

"  When  the  sky  is  remarkably  clear  at  the 
horizon,  and  objects  usually  invisible  are  distin- 
guishable from  each  other,  or  appear  higher  up  by 
refraction,  there  will  be  rain  and  perhaps  wind. 

"  Extraordinary  brilliance  of  the  stars,  lack  of 
distinctness,  or  apparent  multiplication  of  the 
horns  of  the  moon,  halos,  and  fragments  of  rain- 
bows upon  detached  clouds,  indicate  that  the  wind 
will  increase,  and  that  there  will  be  rain." 

M.  Marie-Davy,  in  his  "Instructions  on  the 
Use  of  the  Barometer,"  for  foretelling  changes  of 
the  weather,  has  given  the  result  of  a  comparative 
examination  of  the  meteorological  charts  of  the 
Observatory,  and,  in  so  doing,  has  summed  up  all 
that  is  known  at  the  present  day  concerning  the 
movements  of  the  atmosphere  on  the  surface  of 
Europe.  These  instructions  contain  very  interest- 
ing details  relative  to  the  advance  and  movement 
of  the  whirlwinds  that  take  place  in  the  great 
aerial  current,  the  general  direction  of  which  ex- 
erts a  preponderating  influence  over  the  meteor- 
ological condition  of  the  European  countries. 

Other  observations  were  recommended  by  the 


280         METEORS   AND  METEORIC   PHENOMENA. 

International  Conference  held  at  Brussels  in  1853, 
on  the  invitation  of  the  United  States,  with  a 
view  to  adopt  a  common  system  of  meteorological 
observations  at  sea.  Thus,  thunder-storms  and 
tornadoes  that  occur  in  the  vicinity  of  the  great 
oceanic  currents ;  the  drift  of  floating  ice ;  the 
appearance  of  land  birds  and  insects  out  at  sea ; 
showers  of  dust ;  red  or  white  spots  that  are 
frequently  remarked  on  the  surface  of  the  deep  ; 
the  number  and  direction  of  the  shooting-stars ; 
the  northern  lights,  and  similar  phenomena, 
might  give  some  very  useful  indications  concern- 
ing the  course  and  formation  of  the  meteoric  phe- 
nomena, which  cannot  be  foreseen  with  any  fixed 
degree  of  accuracy,  excepting  by  first  taking  the 
utmost  care  to  collate  and  arrange  observations 
of  every  kind  relative  to  the  circumstances  in 
which  they  occur. 

CHARACTER   OF  FUTURE   SEASONS   AND  YEARS. 

The  attempt  has  been  made  to  foretell  the  char- 
acter of  seasons  and  years  to  come,  but  the  insuf- 
ficiency of  the  data  on  which  the  prognostics 
were  based  has,  thus  far,  rendered  the  endeavor 
nearly  fruitless. 

Nevertheless,  M.  de  Gasparin  reports  that,  in 
1829, 1VL  Hubert-Burnaud,  of  Yverdon,  predicted  a 


CHARACTER  OF  FUTURE  SEASONS  AND  YEARS.   281 

severe  winter  for  1830,  and  it  came  as  he  had  said. 
"  This  was  no  prophecy,"  M.  Burnaud  tells  us, "  but 
a  very  simple  calculation.  South  and  southwest 
winds  having  prevailed  for  six  months,  I  had  a 
right  to  suppose  that  the  north  winds  would  have 
their  turn.  In  the  second  place,  the  sun  having 
been  hidden  during  the  months  of  July  and  Octo- 
ber, it  was  natural  to  think  that  the  earth  would 
be  cooled,  at  its  surface,  more  than  usual.  This 
circumstance,  combined  with  the  presence  of  the 
north  wind,  should  render  the  winter  a  very  cold 
one.  Finally,  the  autumn  having  been  very  rainy, 
the  winter,  according  to  all  appearances,  would  be 
dry.  When  all  these  circumstances  are  partial 
only,  no  conclusion  can  be  drawn ;  but  their  gen- 
eral prevalence,  throughout  Europe,  would  be 
likely  to  produce  simple  effects,  because  there 
would  be  no  disturbing  cause  over  an  immense 
extent  of  space." 

Let  us  add  that,  in  his  important  memoir  on 
the  periodicity  of  severe  winters,  published  in  the 
Annuaire  de  la  Societe  Meteorologique  de  France, 
in  May,  1861,  M.  Renou,  a  learned  meteorologist, 
has  grouped  together  all  the  observations  recorded 
since  the  year  1400,  and  has  deduced  from  them 
some  remarkable  results  in  reference  to  the  peri- 
odical return  of  severe  winters. 


282         METEORS   AND   METEORIC    PHENOMENA. 

"  There  will  soon  be  an  opportunity,"  says  M. 
Renou,  "  to  verify  the  fact  whether  the  periodicity 
that  I  have  announced  for  rigorous  winters  does 
really  exist,  since  the  hardest  winter  of  all  is  to 
occur  about  1861,  and  cannot,  in  my  opinion,  ex- 
perience a  delay  of  more  than  two  years,  as  was 
the  case  in  1709.  Any  postponement,  I  also  be- 
lieve, would  be  compensated  by_  an  exceptional 
intensity  of  the  season." 

The  winter  of  1860  and  that  of  1863  and  '64, 
which  covered  southern  Europe  with  snow  and 
ice,  and  was  very  severe  even  in  Egypt,  partially 
confirmed  M.  Renou's  predictions.  "We  may  be 
permitted,  then,  to  hope  that  the  possibility  of 
foretelling  the  meteorological  character  of  certain 
years  or  certain  periods,  when  based  upon  more 
numerous  and  accurate  observations,  may  one  day 
be  sufficiently  ascertained  to  lead  to  important  re- 
sults, particularly  in  reference  to  agriculture,  the 
leading  source  of  our  wealth  and  comfort. 

SHOOTING-STARS. — INFLUENCE   OF   THE   MOON. 

We  must  here  mention  the  researches  of  M. 
Ooulvier-Gravier,  in  relation  to  the  shooting- 
stars,  whose  appearance  and  direction  enable  us 
to  foretell  changes  of  weather  two  or  three  days 
in  advance.  The  facts  collated  by  this  indefati- 


SHOOTING-STAES. 

gable  observer  in  his  work  entitled  "  Researches  in 
relation  to  Meteors  and  the  Laws  that  govern 
Them,"  published  at  Paris  in  1863,  are  sufficient- 
ly remarkable  to  merit  a  serious  examination,  and 
it  is  to  be  desired  that  the  interesting  researches 
which  he  has  taken  up  should  be  multiplied  in 
number,  so  as  to  ascertain  their  practical  utility. 
Moreover,  we  have  already  indicated  all  the  im- 
portance of  these  researches,  which  will  aid  us  in 
attaining  a  better  comprehension  of  the  limits  and 
constitution  of  the  atmosphere,  the  first  founda- 
tion of  a  more  exact  knowledge  of  meteors,  and 
the  laws  that  govern  their  formation. 

The  influence  of  the  moon  upon  atmospheric 
phenomena,  the  weather,  and  the  seasons,  ad- 
mitted as  it  has  been,  by  mariners,  since  the  days 
of  antiquity,  and  occupying  so  large  a  place  as  it 
does  in  the  ancient  collections  of  agricultural 
maxims,  was  long  denied  by  most  men  of  learn- 
ing, or  regarded  by  them  as  too  weak  to  produce 
any  appreciable  results.  It  is,  nevertheless,  be- 
yond all  doubt  that  the  attraction  of  the  moon 
and  the  sun,  which  produces  the  tides  of  the 
ocean,  occasions  atmospheric  tides,  also ;  and  it  is 
very  probable,  indeed,  that  the  latter  may,  espe- 
cially at  epochs  when  they  are  the  strongest,  de- 
termine changes  in  the  condition  of  the  weather. 
14 


284         METEORS   AND   METEORIC   PHENOMENA. 

Experiments  made  with  the  utmost  care,  by 
the  aid  of  the  barometer,  have  indicated  the 
totality  of  the  movement  imparted  to  the  atmos- 
phere by  the  phases  of  the  moon,  and  the  general 
influence  of  those  phases  on  the  rains  and  on  the 
direction  of  the  wind  is  now  recognized.  But  it 
is  not  easy  to  separate  it  for  each  place  from  the 
secondary  causes  that  tend  to  disguise  it,  and  it 
can  be  reached  only  by  multiplying  observations, 
at  present  so  very  incomplete,  with  a  view  to 
establish  the  probability  of  periodical  variations 
of  the  weather  corresponding  with  the  different 
phases  of  the  moon. 

M.  Arago,  in  a  remarkable  dissertation  *  rela- 
tive to  the  influence  of  the  lunar  phases  on  at- 
mospheric phenomena  and  the  vegetable  realm,  has 
established  incontestable  facts  which,  while  de- 
stroying errors  hitherto  accepted,  still  prove  that 
popular  notions  on  the  subject  are  not  altogether 
without  foundation.  When  based  upon  real  ob- 
servation, they,  on  the  contrary,  may  render  good 
service,  unless  they  should  become  more  injurious 
than  useful  through  the  too  great  importance  at- 
tached to  them.  M.  de  Gasparin  says,  very  justly 

*  "  Annuaire  of  the  Bureau  of  Longitude.  1832,  1833."  See 
also,  in  the  "Annales  Hydrographiques,"  1st  trimestre  of  1864,  the 
note  on  Meteorology  by  Admiral  Fitzroy 


INFLUENCE   OF  THE  MOON.  285 

on  this  subject,  that  "  there  are  scientific  preju- 
dices, as  there  are  popular  prejudices,  but  in  no 
age  have  learned  men  been  more  disposed  to  give 
up  theirs,  and  to  submit  them,  in  good  faith,  to 
the  crucible  of  experiment  and  observation.  The 
people  themselves,  too,  no  longer  cling  with  the 
same  tenacity  to  their  superstitious  ^ideas,  and 
manifest  much  greater  readiness  to  listen  to  the 
voice  of  reason." 


CHAPTEK  XII. 

PRACTICAL  METEOROLOGY. 


The  Brussels  Conference.— Meteorological  Practice. —Instruments  of 
Observation.— Telegraphic  Meteorology.— The  Hurricane  of  Decem- 
ber 2,  1863. — Alarm-Signals. — Rural  Meteorology. — Association  for 
the  Advancement  of  Meteorology. 


THE   BRUSSELS   CONFERENCE. 

ADMIRAL  FITZROY  has  collected,  in  an  excellent 
work  called  "  The  Book  of  the  "Weather,"  pub- 
lished at  London  in  1863,  the  most  familiar 
notions  concerning  meteorology,  and  has  made 
known  the  combinations  recently  adopted  in  the 
principal  observatories  of  Europe  and  the  United 
States,  in  order  to  be  able  to  give,  either  daily  or 
on  the  approach  of  storms,  some  rational  an- 
nouncement of  the  anticipated  change  in  the 
weather.  "We  have  summed  up,  in  a  work  en- 
titled "  Storms,"  with  very  considerable  fulness 
of  detail,  the  substance  of  what  has  been  done,  up 
to  the  present  time,  to  attain  this  important  re- 


THE   BETJSSELS   CONFERENCE.  287 

suit ;  and  we  have  shown,  by  enumerating  the 
services  already  rendered,  all  that  could  be  hoped 
for  in  the  early  future.  Returning  here,  briefly, 
to  the  same  subject,  we  are  happy  that  we  have 
it  in  our  power  to  bear  testimony  to  the  rapid 
progress  realized  since  the  organization  of  the  Im- 
perial Observatory  at  Paris,  a  progress  that  leaves 
no  doubt  remaining  as  to  the  rank  that  meteor- 
ology is  destined  to  take  among  the  most  useful 
of  the  sciences,  and  those  that  are  best  adapted  to 
aid  man  in  his  labors,  by  giving  him  a  more  cor- 
rect idea  of  the  universal  order  that  presides  over 
all  things. 

It  is  to  a  learned  officer,  formerly  of  the  United 
States  naval  service,  Commander  Maury,  that  we 
owe  the  first  idea  of  a  great  association  to  unite 
all  the  most  advanced  nations  in  one  common 
system  of  meteorological  observations,  and  in- 
tended to  include  the  entire  globe,  or  at  least  all 
those  regions  to  which  the  light  of  science  and 
civilization  has  penetrated  in  our  day. 

A  conference,  in  which  the  principal  states  of 
Europe  were  represented,  met  at  Brussels  in  1853, 
M.  Quetelet,  the  director  of  the  Royal  Observa- 
tory at  Brussels,  presiding.  The  object  was,  as 
we  have  said,  to  come  to  an  understanding  in 
reference  to  the  adoption  of  a  uniform  system  of 


288        METEORS  AND  METEOKIC  PHENOMENA. 

observations  at  sea.  Maury,  who  was  then  the 
director  of  the  National  Observatory  at  "Wash- 
ington, represented  his  government  at  this  meet- 
ing, and  we  here  quote  a  part  of  his  address,  in 
which  he  explained  to  those  present  the  purpose 
of  his  mission : 

"  The  proposition,  in  consequence  of  which  the 
American  Government  has  thought  tit  to  call  for 
the  present  meeting,  emanates  from  the  English 
Government.  It  consists  of  the  communication 
of  a  project  drawn  up  by  Captain  Henry  James 
of  the  Koyal  Engineers,  by  order  of  Sir  John  Bur- 
goyne,  inspector-general  of  fortifications,  and  in 
which  the  Government  of  the  United  States  was 
invited  to  take  part. 

"  Nineteen  stations  have  been  established  by 
England,  in  pursuance  of  a  uniform  system,  and 
the  observations  have  been  placed  under  the  im- 
mediate direction  of  the  officer  of  engineers  com- 
manding at  each  station. 

"  The  American  Government  accepted  the 
proposal  of  the  English  Government,  and,  on 
condition  that  the  plan  of  observation  should  be 
extended  to  the  sea  and  made  universal,  promised 
its  cooperation.  I  was  then  intrusted  with  the 
duty  of  placing  myself  in  communication  with 
the  owners  and  the  captains  of  the  naval  and 


THE  BRUSSELS   CONFERENCE.  289 

mercantile  marine,  for  the  execution  of  the 
plan. 

"  It  was  by  the  aid  of  information  extracted 
from  more  than  a  thousand  log-books  that  I  have 
been  enabled  to  prepare  the  charts  of  tracks, 
winds,  and  currents,  that  have  been  published  up 
to  the  present  time. 

"In  order  to  give  still  more  extension  to 
nautical  observations,  the  Government  of  the 
United  States  has  decided  that  an  appeal  should 
be  made  to  all  maritime  nations  to  induce  them 
to  adopt  a  uniform  model  of  log-book. 

"  The  aim  of  our  assembling  is,  therefore,  to 
come  to  a  common  understanding  with  reference 
to  a  uniform  method  of  nautical  and  meteorologi- 
cal observations  taken  at  sea.  I  am  already  in- 
debted to  the  courtesy  of  one  of  the  members 
present,  M.  Jansen,  lieutenant  in  the  navy  of  the 
Netherlands,  for  an  extract  from  the  log-book  kept 
on  board  of  a  Dutch  man-of-war,  and  it  may  be 
cited  as  an  example  of  what  may  be  expected  of 
expert  and  careful  observers.  In  order  to  secure 
regularity  in  the  distribution  of  the  charts  that 
the  American  Government  offers  gratuitously  to 
captains  of  every  nationality,  I  would  express  the 
wish  that  a  person  should  be  designated  by  the 
government  of  each  country  to  collect  and  com- 


290         METEOKS   AND   METEOEIC    PHENOMENA. 

pile  the  extracts  from  log-books  to  which  I  have 
had  the  honor  of  calling  your  attention.  It  is 
through  his  hands  that  the  charts  would  be  con- 
veyed to  the  parties  for  whom  they  were  des- 
tined." 

We  shall  not  here  enumerate  all  the  resolutions 
adopted  by  the  Conference,  as  we  did  in  a  work 
entitled  "  The  Phenomena  of  the  Sea  and  the  At- 
mosphere," and  more  special  in  its  nature.  But 
we  think  it  right  to  recall  the  fact  that  it  was  the 
starting-point  for  the  researches  which  have  ex- 
tended so  far  since  then,  and  have  been  the  source 
of  important  progress  in  meteorology.  May  we 
not  be  allowed,  at  the  same  time,  to  remark  that, 
if  the  most  wonderful  of  the  Divine  works,  in  the 
order  of  material  things,  be  the  power  of  the  laws 
that  maintain  the  harmony  of  the  universe,  there 
is  in  the  moral  order  no  more  gratifying  subject 
of  contemplation  than  the  laws  which  govern  the 
progress  of  communities,  and  which  stand  forth  in 
better  relief  in  our  day,  in  the  happy  tendencies 
of  Christianity  toward  association — in  other  words, 
toward  union  of  sentiment  and  effort  ? 

The  Meteorological  Bureau  of  Utrecht,  under 
the  direction  of  M.  Buys  Ballot,  a  learned  profess- 
or, and  established  in  order  to  centralize  the  ob- 
servations made  by  the  navy  of  Holland,  was  the 


METEOROLOGICAL    PRACTICE.  291 

first  establishment  in  Europe  that  cooperated 
with  Commander  Maury's  labors.  Lieutenant 
Jansen,  a  distinguished  officer,  who  from  the  out- 
set had  applied  himself  with  the  most  intelligent 
zeal  to  the  new  system  of  research  pursued  on  the 
ocean,  was  attached  to  this  bureau. 

Belgium,  Sweden,  Norway,  Denmark,  Portu- 
gal, Spain,  the  free  city  of  Hamburg,  and  the  re- 
public of  Bremen,  soon  followed  the  example  set 
by  Holland.  The  British  Government  also  was 
one  of  the  first  to  establish  a  bureau  commissioned 
to  arrange  and  discuss  the  observations  collected 
by  English  ships  upon  all  the  waters  of  the  globe, 
in  accordance  with  the  plan  recommended  by  the 
Brussels  Conference.  Most  of  the  great  Powers, 
also,  had  accepted  this  plan,  and  expressed  their 
intention  to  put  it  in  execution,  by  means  of 
the  vessels  sailing  under  their  flag.  These,  to  use 
Commander  Maury's  expression,  would,  for  the 
time  being,  have  been  made  so  many  floating  ob- 
servatories, on  board  of  which  our  common  effort 
for  the  advancement  of  science  and  the  good  of 
humanity  would  be  going  on. 

METEOROLOGICAL    PRACTICE. 

But  it  was  easy  to  foresee  that  the  ocean  could 
not  remain  the  only  subject  of  systematic  study, 


292         METEORS    AND   METEORIC   PHENOMENA. 

and  Maury  subsequently  asked  for  another  confer- 
ence, with  a  view  to  proposing  a  plan  of  terrestrial 
observations,  "  so  that  meteorology  should  be  en- 
abled, at  last,  to  move  onward  in  a  path  truly 
universal." 

It  is  evident  that  in  this  direction  alone  can 
we  hope  to  discover  the  great  laws  that  govern 
the  movements  of  the  atmosphere — laws  of  which 
we  now  have  but  a  glimpse,  and  the  knowledge  of 
which  would  furnish  the  most  solid  foundation  to 
meteorological  studies. 

The  nature  of  the  researches  necessary  to 
attain  this  result,  not  only  demands  the  widest 
range  of  observation,  but  those  engaged  in  it 
must  be  able  to  correspond  with  such  rapidity  as 
to  announce  the  appearance  of  phenomena,  and 
to  follow  their  progress ;  and  the  employment 
of  the  electric  telegraph  has  arisen  to  give  mete- 
orology this  powerful  means  of  investigation. 

It  is  around  the  great  lakes  of  America,  where 
disasters  are  so  frequent,  that  this  system  of  com- 
munication was  first  put  in  play  to  signal  the  ap- 
proach of  storms ;  adopted,  subsequently,  by  the 
principal  states  of  Europe,  it  has  already  rendered 
the  greatest  service  to  navigators,  and  should  like- 
wise aid  in  diminishing  the  losses  that  unexpected 
bad  weather  so  often  inflicts  upon  agriculture. 


INSTRUMENTS   OF   OBSERVATION.  293 

Rapidly  organized  in  England,  thanks  to  the 
zeal  and  devotion  of  Admiral  Fitzroy,  the  system 
of  telegraphic  warnings  has  been  inaugurated  in 
France  also,  through  the  efforts  of  an  illustrious 
savant,  M.  le  Terrier,  the  director  of  the  Imperial 
Observatory.  The  ministry  of  marine  in  that 
country  has,  also,  on  its  part,  decreed  the  estab- 
lishment of  a  meteorological  service  in  the  sea- 
ports, combined  with  the  similar  service  in  Eng- 
land, and  the  recent  construction,  along  the  whole 
extent  of  the  French  sea-coast,  of  signal-light 
houses  connected  with  the  grand  net-work  of 
electric  telegraphs,  admits  of  the  transmission  of 
warnings  to  all  the  threatened  points,  and  even  to 
vessels  that  may  be  passing  in  sight  of  the  coast. 
It  may  be  readily  understood  how  the  generaliza- 
tion of  such  a  surface  is  as  advantageous  to  the  in- 
terests of  navigation  as  to  the  progress  of  science, 
and  we  shall  see  this  still  more  clearly  as  we  take 
up  some  details  of  the  organization  of  meteorolo- 
gical observatories. 

INSTRUMENTS   OF   OBSERVATION. 

Among  the  instruments  of  physical  science 
which  serve  to  determine  atmospheric  variations, 
the  barometer  is  one  of  those  that  are  most  usually 
consulted.  All  mariners  have  had  the  opportu- 


294          METEORS    AND   METEORIC   PHENOMENA. 


nity  to  remark  the  usefulness  of  the  indications 

that  it  yields  previously  to  rain  and  gales  of  wind. 

But  these  indications,  being  relative  to  the  weight 
of  the  column  of  air  that 
causes  the  column  of  mer- 
cury to  oscillate,  do  not  tell 
us  in  what  case  that  weight 
increases  or  diminishes,  and, 
in  order  to  arrive  at  a  more 
exact  foreknowledge  of  phe- 
nomena, it  is  necessary  to  as- 
certain, by  the  thermometer 
and  the  hygrometer,  the  dif- 
ferent causes  that  may  influ- 
ence the  weight  of  the  atmo- 
spheric strata.  Thus,  for  ex- 
ample, the  variation  of  these 
two  instruments,  especially 
during  the  winter  season, 
may  indicate,  in  the  absence 
of  barometrical  signs,  the  ap- 
proach of  cold  and  dry  north 
winds,  or  warm  and  moist 
south  winds,'  the  predomi- 
nance of  which  determines 
the  character  of  the  weather. 

If  these  winds,  in  their  general  character,  differ, 


INSTRUMENTS    OF    OBSERVATION.  295 

as  Admiral  Fitzroy  thinks  they  do,  and  as  we 
should  feel  inclined  to  admit,  in  their  electrical 
condition,  the  indications  of  a  curious  instru- 
ment entitled  the  storm-glass  must  not  be  neg- 
lected, that  condition  no  doubt  having  a  great 
influence  upon  the  atmospheric  phenomena,  that 
may  modify  the  pressure  of  the  atmosphere. 

The  storm-glass,  used  in  England  more  than 
a  century  ago,  and  taken  up  again  by  Admiral 
Fitzroy,  is  composed  of  a  glass  tabe,  hermetically 
sealed,  containing  a  chemical  mixture,  the  aspect 
of  which  varies  according  to  the  direction  of  the 
wind,  and  not  according  to  its  force;  that  is -to 
say,  remarks  the  admiral,  "  according  to  the 
special  character,  and  very  probably  according  to 
the  electric  tension,  of  the  aerial  current." 

"We  have  had  the  opportunity  to  watch  the 
workings  of  one  of  these  instruments  for  several 
months,  and  we  have  often  seen  it  indicate  with 
remarkable  precision  the  violent  storms  of  the 
north,  and  the  abundant  rains  that  accompany  the 
great  aerial  currents  of  the  south. 

Still  other  instruments  are  employed  in  the 
observatories,  as,  for  instance,  the  psychrometer, 
or  damp-bulb  thermometer,  which  indicates  the 
quantity  of  vapor  in  the  atmosphere ;  the  pluvi- 
ometer, which  marks  the  quantity  of  rain  fallen  ; 


296         METEORS   AND   METEORIC   PHENOMENA. 

the  surface  plate,  by  which  the  force  of  the  wind 
is  measured  through  the  pressure  exerted  upon  it ; 
the  electrometer,  that  notes  the  electricity  in  the 
air ;  the  prepared  papers,  by  the  exposure  of  which 
to  the  atmosphere,  and  their  subsequent  compar- 
ison with  each  other,  the  quantity  of  ozone  or 
electrified  oxygen  is  ascertained  through  its  prop- 
erty of  modifying  their  colors ;  and,  finally,  certain 
special  instruments  destined  to  indicate  the  mag- 
netic condition  of  the  earth. 

TELEGRAPHIC   METEOROLOGY. 

It  is  evident  that  the  atmospheric  condition 
of  any  region  is  subjected  to  the  influence  of  the 
surrounding,  and,  in  certain  circumstances,  to  that 
of  other  very  distant,  regions.  An  observatory 
daily  receiving,  from  all  the  chief  points  of  a  wide 
extent  of  territory,  like  that  which  embraces 
Europe  and  the  banks  of  the  Mediterranean,  tele- 
grams stating  the  condition  of  the  weather  at 
each  of  those  points,  could  not  only  preannounce 
the  atmospheric  variations  for  the  place  in  which 
it  is  situated,  but  likewise  for  each  of  the  places 
with  which  it  is  in  correspondence.  Such  is  now 
the  position  of  the  most  important  observatories 
of  Europe,  and  principally  of  the  one  in  Paris, 
which  has  been  justly  designated  by  Admiral  Eitz- 
roy  as  "  a  grand  centre  of  telegraphic  alliance." 


TELEGRAPHIC   METEOROLOGY.  297 

This  observatory  now  publishes  daily  a  bul- 
letin containing  the  data  that  are  collected  there 
every  three  hours,  as  well  as  those  that  are  fur- 
nished to  it  at  eight  o'clock  in  the  morning,  by 
about  fifty  correspondents  distributed  over  the 
whole  surface  of  Europe.  These  data  embrace 
the  barometric  pressure,  the  temperature,  the  di- 
rection and  the  force  of  the  lower  strata  of  winds, 
the  state  of  the  sky,  and  the  condition  of  the  sea 
upon  the  coast,  at  each  station.  Along  with  the 
meteorological  chart  of  the  day,  prepared  under 
the  direction  of  M.  Marie-Davy,  is  a  summary 
statement  of  the  general  character  of  the  atmos- 
phere, drawn  up  by  that  distinguished  savant, 
with  a  forecast  of  the  probable  state  of  the  weath- 
er on  the  ensuing  day.  These  probabilities  have 
reference  to  fourteen  regions,  or  districts,  into 
which  the  European  seaboard  has  been  marked 
off. 

Curves  corresponding  to  the  barometric  press- 
ure, divided  by  intervals  of  five  millimetres,  are 
traced  on  this  meteorological  chart.  The  press- 
ure of  the  atmosphere  in  Europe  experiences  fre- 
quent variations,  and  it  is  in  the  proximity  or 
separation  of  those  curves  that  the  principal  ele- 
ments of  a  rational  foreknowledge  of  the  weather 
are  to  be  found. 


298         METEORS   AND   METEORIC   PHENOMENA. 
THE   HURRICANE    OF   DECEMBER    2. 

This  useful  application  of  telegraphic  meteor- 
ology was  scarcely  realized  when  a  terrible  hurri- 
cane occurred  to  demonstrate  its  efficacy.  This 
hurricane,  which  was  analogous  to  the  cyclones  of 
the  tropical  regions,  swept  across  France  between 
the  2d  and  the  4th  of  December,  1863.  Its  in- 
fluence was  felt  as  early  as  the  28th  of  November, 
the  time  when  it  was  on  the  ocean,  as  high  up  in 
latitude  as  the  south  of  Spain.  On  the  27th  and 
the  28th  the  bulletin  had  already  announced  the 
condition  of  the  atmosphere  as  very  doubtful. 
Until  the  1st  of  December,  the  whirlwind  as- 
cended toward  the  north,  and  was  then  signalled 
from  the  northwest  of  England.  "  The  rapid  fall 
which  has  been  noted  this  morning  in  Ireland," 
said  M.  Marie-Davy,  "  the  position  of  the  curves 
of  equal  barometric  pressure,  and  the  easterly 
trending  of  the  winds,  which  have  gathered 
strength  in  the  south  and  southwest,  show  that 
this  phenomenon  is  inclining  eastwardly,  to  strike 
the  coasts  of  Europe  toward  the  north  of  England. 
The  storm,  which  will  probably  extend  over  all 
France,  seems  likely  to  be  severe."  And,  in  fact, 
on  the  morning  of  the  2d,  the  mercury  fell  with 
extreme  rapidity  in  England  and  France.  The 


THE  HUEEICANE  OF  DECEMBER  2.      299 

whirlwind  had  then  swept  down  upon  the  former 
country,  and  had  its  centre  near  Liverpool. 

As  early  as  the  30th,  the  seaports  from  Dun- 
kirk to  Nantes  had  been  forewarned  by  telegraph 
that  they  were  threatened  with  a  gale.  On  the 
1st  of  December,  at  noon,  all  the  ocean -ports 
were  notified  that  a  heavy  storm,  coming  from 
the  southwest,  was  bearing  down  upon  England 
and  France.  Dispatches  sent  on  the  2d  will  give 
some  idea  of  the  activity  that  the  meteorological 
service  displays  in  perilous  circumstances  : 

"At  eight  o'clock  in  the  morning,  the  storm 
did,  in  fact,  burst  upon  the  north  and  a  part  of 
the  west  of  France.  Paris  and  Bordeaux  feel  a 
violent  wind,  but  at  Lyons,  Limoges,  and  Ba- 
yonne,  the  wind  is  still  weak. 

"  At  noon,  all  the  ports  of  the  Mediterranean 
were  again  informed  that  they  were  seriously 
threatened.  Madrid  received  the  same  dispatch 
in  reference  to  the  seaports  on  the  G-ulf  of  Lyons. 
Turin  was  likewise  notified  for  the  north  coasts 
of  Italy  and  as  far  as  Leghorn.  At  fifty  minutes 
past  one,  it  was  repeated  for  the  benefit  of  the 
ports  along  the  coasts  from  Civita  Yecchia  to 
Palermo." 

Admiral  Fitzroy's  telegrams  had  also  notified 
our  ocean-ports  in  advance.  They  announced  that 


300         METEORS   AND  METEORIC   PHENOMENA. 

the  English  coasts  were  covered  with  the  warning 
signals. 

The  Observatory  of  Paris  remained  for  some 
time  without  knowing  whether  its  last  dispatches 
had  reached  their  destination.  Along  several 
lines  the  storm  had  prostrated  the  telegraph-poles 
and  broken  the  wires.  But  communication  re- 
mained open  for  a  length  of  time  sufficient  for 
the  transmission  of  the  most  important  telegram : 
"  On  the  2d  of  December,  during  the  daytime,  I 
received  the  two  dispatches  stating  that  a  severe 
storm  was  about  to  traverse  France,"  writes  the 
president  of  the  Toulon  Chamber  of  Commerce  to 
M.  le  Terrier.  "  They  were  published  and  posted 
up  immediately,  and  the  merchant-vessels  in  the 
roadstead  had  time  to  provide,  and  did  so  pro- 
vide, against  all  risks.  The  maritime  prefecture, 
on  its  behalf,  directed  all  officers  who  were  ashore 
to  hasten  on  board  of  their  vessels.  The  storm 
burst  forth  with  all  its  fury  about  half-past  three 
o'clock  in  the  afternoon.  The  first  telegram  sent 
on  the  2d,  confirming  that  of  the  day  before, 
had  therefore  gained  four  hours'  time  ahead  of 
the  storm,  and  every  thing  was  ready  to  meet  the 
emergency.  Thanks  to  the  precautions  thus  tak- 
en, there  was  no  damage,  no  disaster  to  deplore." 

The  telegrams  forwarded  to  Turin  were  im- 


THE   HURRICANE   OF   DECEMBER   2.  301 

mediately  communicated  to  the  ports  on  the 
western  coast  of  Italy.  The  following  note  was 
published  on  the  3d  in  the  Giornale  di  Genova 
(Genoese  Journal) : 

"  The  prediction  of  the  Paris  Observatory  was 
fully  realized.  The  first  signs  of  the  storm  were 
felt  yesterday  about  7.30  p.  M.  During  the 
night  it  raged  furiously ;  but  there  appears,  nev- 
ertheless, to  have  been  no  disastrous  occurrence  in 
our  neighborhood.  The  commandant  of  the  port 
had  hastened  to  take  all  proper  measures,  and  we 
may  be  thankful  for  them." 

As  soon  as  the  principal  ports  of  the  Channel 
and  the  Ocean  had  received  the  warning  tele- 
grams, they  communicated  them  to  the  entire 
coast  by  means  of  the  electric  signal  stations  that 
have  recently  been  established  there.  The  num- 
ber of  disasters  was,  however,  great  enough  in 
those  waters  to  cause  surprise.  Relatively  to  the 
direction  of  the  wind,  which  beat  on  the  coast  as 
a  general  thing,  it  was  more  difficult  to  take  pre- 
cautions, and,  on  the  other  hand,  again,  there 
must  have  been  some  negligence  in  regard  to 
them. 

The  best  ideas  penetrate  the  minds  of  men 
but  slowly,  and  there  are,  unfortunately,  many 
navigators  still  who  do  not  take  the  warnings 


302         METEOKS   AND   METEORIC   PHENOMENA. 

thus  telegraphed  to  them  seriously  enough.  For 
a  considerable  period  it  required  special  instructors 
in  England  to  give  sailors  and  fishermen  more 
accurate  ideas  on  this  subject. 

The  storm  burst  upon  the  northern  coasts  of 
France  with  extreme  suddenness  and  violence. 
At  Cherbourg,  for  instance,  there  was  very  little 
wind  and  sea  in  the  morning ;  small  boats  could 
navigate  in  the  offing.  The  barometer,  however, 
coincided  with  the  warnings  given,  in  marking 
signs  of  bad  weather.  At  eight  o'clock  it  had 
gone  down  seven  hundred  and  thirty-seven  milli- 
metres. At  ten  o'clock  the  storm  came  on  like  a 
clap  of  thunder.  Parts  of  buildings  were  knocked 
down,  and  roofs  torn  off.  In  the  roadstead,  the- 
sea  was  hurled  aloft  in  whirling  masses,  and 
formed  a  thick  curtain  of  sprayey  mist.  Enor- 
mous billows  beat  over  the  breakwater. 

A  pinnace,  belonging  to  the  iron-clad  frigate 
La  Couronne,  had  set  out  to  assist  a  merchant 
vessel  that  was  nearly  in  a  sinking  condition. 
After  reaching  it,  the  pinnace  was  towing  it  in 
to  moorings  when  the  storm  burst  forth  with  its 
full  fury.  A  small  steamer  from  the  port  came 
to  its  assistance  for  some  time,  but  was  obliged  to 
drop  the  tow  in  order  to  escape  sinking  itself. 
The  tide  was  running  out,  and,  while  the  vessel 


THE  HURRICANE  OF  DECEMBER  2.      303 

was  borne  onward  to  be  wrecked  on  a  less  peril- 
ous beach,  the  pinnace  was  carried  out  to  sea.  It 
was  lost  to  view,  and  in  the  evening  two  sailors, 
covered  with  cuts  and  bruises,  and  both  insensi- 
ble, were  picked  up  near  Cape  Levi.  They  had 
but  a  confused  recollection  of  the  disaster,  and 
were  the  sole  survivors  of  the  boat's  crew,  which 
was  commanded  by  M.  de  Besplas,  a  gallant  offi- 
cer. The  men  were  intrepid,  and,  led  by  a  worthy 
chief,  did  not  hesitate  to  sacrifice  their  life  in 
order  to  accomplish  an  act  of  self-devotion  and 
humanity. 

The  reports  from  London  declared  that  no 
such  formidable  storm  had  been  seen  there  since 
1823.  It  everywhere  presented  the  same  char- 
acter as  at  Cherbourg,  excepting  differences  in  the 
direction  of  the  wind  and  in  the  secondary  phe- 
nomena. At  Strasburg,  it  was  not  until  the  3d, 
about  four  o'clock  in  the  afternoon,  that  heavy 
clouds  covered  the  sky  in  a  moment.  Immedi- 
ately, rain,  snow,  and  hail,  driven  by  a  furious 
wind,  drenched  the  streets  and  squares.  In  the 
south,  on  the  contrary,  a  dry  and  cold  north  wind 
blew  a  storm,  at  first  under  a  clear  sky. 

The  Observatory  proposed  to  make  a  study  of 
this  storm,  as  a  totality,  by  means  of  the  exact  in- 
dications procurable  at  all  the  stations  lying  with- 


304         METEOKS   AND   METEORIC   PHENOMENA. 

in  its  range.  This  study,  the  first  part  of  which 
was  published  in  the  Bulletin  of  March  31,  1864, 
will,  no  doubt,  be  very  prolific  of  results  for  me- 
teorological science,  as  were  the  similar  labors  of 
Admiral  Fitzroy,  after  the  great  storm  of  Octo- 
ber, 1859. 

The  theory  of  cyclones,  founded  by  the  Red- 
fields,  the  Eeids,  and  the  Piddingtons,  embraces 
the  general  laws  of  their  translation  and  rota- 
tion. It  has  furnished  practical  rules  for  the  man- 
agement of  vessels ;  but  it  still  leaves  many  gaps, 
which  the  new  studies  of  to-day,  aided  by  the  elec- 
tric telegraph,  will  powerfully  assist  in  filling. — 
The  point  of  view  taken  by  the  Observatory  ap- 
pears to  us,  moreover,  excellent,  and  we  earnestly 
hope  that  the  extension  of  the  meteorological  ser- 
vice will  soon  render  it  possible  to  extend  these 
researches  over  a  larger  basis.* 

"  If  our  charts,"  said  M.  Marie-Davy,  in  a  note 
sent  in  to  the  Academy  of  Sciences,  "  enable  us  to 
foretell  a  storm,  and  tg  follow  it  in  its  course 
across  the  Continent  of  Europe,  they  tell  us  noth- 
ing, or  almost  nothing,  concerning  the  place  of 
their  origin  and  their  mode  of  formation,  and  nev- 
ertheless that  is  one  of  the  essential  elements,  not 

*  In  M.  Marie-Davy's  interesting  work  entitled  "  The  Move- 
ments of  the  Atmosphere  and  the  Sea,  considered  in  reference  to 
Foretelling  the  State  of  the  Weather." 


ALABM-SIGNALS.  305 

only  of  the  science,  but  of  its  application.  We  at- 
tach the  greatest  importance  to  the  construction 
of  daily  charts,  embracing  the  whole  Northern 
Hemisphere,  were  it  to  require  a  whole  year  to 
bring  together  the  necessary  elements  for  each 
one  of  them.  In  the  midst  of  the  incessant  shift- 
ing and  changing  of  atmospheric  phenomena,  the 
important  point  is,  very  certainly,  to  extract  from 
them  great  general  laws,  and  the  search  for  these 
may  be  aided  by  the  investigations  of  preceding 


years." 


ALARM-SIGNALS. 


The  alarm-signals  employed  in  England  to 
announce  the  approach  of  storms  consist,  in  the 
daytime,  of  three  figures  made  of  strong  canvas, 
which  are  hoisted  on  the  mast  of  the  signal-sta- 
tions, and  can  be  seen  at  a  great  distance. 

A  cone,  with  the  point  turned  toward  the  sky, 
announces  that  there  is  some  likelihood  of  a  storm 
from  the  north. 

Placed  with  its  point  downward,  the  cone  indi- 
cates the  approach  of  a  storm  from  the  south. 

A  cylinder  is  the  signal  for  a  hurricane  or  a 
rotating  tempest. 

If  the  cone  be  placed  with  the  point  upward 
above  the  cylinder,  the  storm  that  threatens 
comes  from  the  north. 


306         METEORS   AND   METEORIC    PHENOMENA. 

If  the  cone,  on  the  contrary,  be  under  the  cyl- 
inder, with  its  point  turned  toward  the  ground, 
the  hurricane  comes  from  the  south. 

During  the  night,  lanterns,  arranged  as  they 
are  seen  in  the  accompanying  illustration,  in  such 
manner  as  to  represent  the  cones  or  the  cylinder, 
take  the  place  of  the  day- signals. 

These  signals,  which  are  very  simple,  and  of 
easy  manipulation,  will,  no  doubt,  be  generally 
adopted  wherever  the  organization  of  the  meteor- 
ological service  is  such  as  to  admit  of  the  prean- 
nouncement  of  storms. 

On  the  coasts  of  the  kingdom  of  Italy,  mar- 
iners are  forewarned  that  a  storm  threatens  them 
by  a  red  flag  hoisted  on  all  the  towers  and  light- 
houses of  the  principal  localities,  ranging  from 
Genoa  to  Palermo,  and  thence  up  along  the  Adri- 
atic. 

This  signal  is  employed  only  when  it  may  be 
inferred  from  the  meteorological  Bulletin^  sent  by 
the  director  of  the  Observatory  at  Paris,  that  a 
tempest  is  approaching.  The  telegram  that  an- 
nounces it  is  moreover  posted  up  in  all  the  sea- 
ports, and  transmitted  to  the  Chambers  of  Com- 
merce. 

On  the  most  dangerous  points  of  the  coast  of 
England,  where  the  fishing-boats  and  small  craft, 


i) 


ALAKM-SIGNALS.  p.  806 


15 


AGRICULTURAL    METEOROLOGY.  307 

that  perform  the  service  of  the  coast,  are  exposed 
to  formidable  gales,  even  during  the  fine  season, 
barometers  put  up  by  the  meteorological  bureau 
assist  in  foretelling  bad  weather.  French  ocean- 
ports  have  received  from  the  ministry  of  the  ma- 
rine instruments  destined  for  the  same  service ;  and 
the  recent  adoption  by  France  and  England  of  a 
code  of  signals  that  offers  to  all  nations  a  uniform 
means  of  communicating  at  sea,  will  enable  ves- 
sels provided  with  the  necessary  material,  the 
price  of  which  is  very  moderate,  to  put  themselves 
in  communication  with  the  signal-stations,  and  to 
receive  the  latest  meteorological  warnings  from 
them. 

AGRICULTURAL   METEOROLOGY. 

M.  le  Yerrier — in  his  reply  to  the  ministry  of 
Public  Instruction,  on  the  subject  of  the  obser- 
vations that  it  would  be  possible  to  organize  in 
France,  in  order  to  obtain  data  useful  to  agricul- 
ture— recently  said :  "  The  reception,  accorded  by 
our  maritime  populations,  of  the  warnings  fur- 
nished them  by  the  Observatory  causes  us  to  fore- 
see the  time  at  hand  when  our  farmers  will  claim 
similar  attention  from  the  solicitude  of  the  gov- 
ernment. 

"Your  excellency  will,  no  doubt,  remember 


308         METEOKS   ANT)   METEOKIO   PHENOMENA. 

that  it  was  the  urgent  request  of  Prussia,  on  be- 
half of  a  society  of  agriculturists  at  Mecklenburg, 
that  gave  occasion  to  our  first  dispatches  predict- 
ing the  state  of  the  weather,  and  that  as  early  as 
1854,  after  a  storm  that  had  devastated  Provence, 
after  having  raged  at  Havre  twenty-four  hours 
earlier,  the  Agricultural  Board  of  Toulon  (Yar) 
addressed  a  long  letter  to  the  Minister  of  Agricul- 
ture, in  order  to  set  forth  to  him  the  advantages 
that  would  result  from  the  preannouncement,  at 
the  right  time,  of  the  approach  of  bad  weather. 

"  I  think,  then,  M.  Minister,  that  not  only  is 
there  fair  occasion  to  encourage  the  good  intentions 
of  the  Normal  School  of  Yesoul,  which  asked  for 
authority  to  have  its  pupils,  under  the  direction  of 
a  master,  daily  take  meteorological  observations, 
to  be  published  in  the  Journal  of  Practical  Ag- 
riculture, but  that  there  would  be  great  utility  in 
extending  this  measure  to  all  the  normal  schools 
in  the  empire.  No  one  would  hesitate  for  a  mo- 
ment to  take  charge  of  this  work. 

"  The  instruments  necessary  for  each  school 
are: 

A  barometer 80  franca 

A  thermometer 20      " 

A  pluviometer 30 

An  hygrometer 25 

Total. . .  156  francs. 


AGRICULTURAL   METEOROLOGY.  309 

"  The  agricultural  societies,  the  rural  boards, 
and  the »  councils-general,  could  contribute  the 
means  to  defray  this  expense. 

"  Meteorology  is  taking  a  rank  less  and  less 
disputed  among  our  sciences  of  general  applica- 
tion, and  public  attention  is  fixed  upon  the  ser- 
vices it  is  called  upon  to  render  to  our  people. 
The  moment  seems,  then,  to  have  arrived  for  se- 
rious effort  in  organizing  the  means  of  study  that 
are  indispensable  to  it." 

In  a  subsequent  letter  M.  le  Yerrier  called  the 
attention  of  the  Minister  of  Public  Instruction  to 
the  numerous  tempests  that  crossed  over  Europe 
during  the  month  of  May,  1864,  and,  in  remark- 
ing the  fact  that  the  storm-gusts  of  summer  seem 
to  "  have  the  same  origin  as  the  great  tempests  of 
the  bad  season,  and  that  both  may  be  followed,  as 
well  as  foreseen,  in  their  progress  by  the  same 
means,"  he  asked  the  concurrence  of  the  normal 
schools,  the  Chambers  of  Commerce,  the  agricul- 
tural societies,  and  government  engineers,  in  get- 
ting together  the  materials  of  a  good  statistical 
statement  of  storms,  that  would  render  it  possible 
to  prepare  charts  of  the  regions  traversed  by  those 
meteors,  and  determine  the  probabilities  of  storms 
for  each  district.  It  will  be  easily  understood 
that  such  charts  might  not  merely  assist  in  fore- 


310         METEOKS   AND   METEORIC   PHENOMENA. 

warning  farmers,  but  that  they  would,  moreover, 
present  a  means  of  proportioning  the  sacrifices 
each  individual  would  have  to  make,  in  a  system 
of  mutual  insurance,  to  his  chances  of  loss. 

In  reply  to  this  letter,  the  minister  saw  fit  to 
issue  a  circular  to  the  prefects,  asking  the  concur- 
rence of  the  council-general  of  each  department  in 
providing  the  necessary  instruments,  so  as  to  put 
the  normal  schools  in  a  position  to  collect  the  ob- 
servations indicated  by  M.  le  Yerrier. 

If  we  consider,  as  Messrs.  Payen  and  Barral 
have  done,  in  their  remarkable  report  *  upon  the 
possible  application  of  meteorology  to  agriculture, 
all  the  advantages  that  would  result  to  our  rural 
districts  from  a  knowledge  of  the  weather  based 
upon  observations  more  certain  than  the  usual 
signs,  we  may  hope  that  one  day  each  of  our  vil- 
lages, like  each  of  our  seaports,  will  possess  the 
necessary  meteorological  instruments,  obtained 
either  by  means  of  a  moderate  assessment  or  a 
contribution  from  the  townships  and  communes. 
The  tutor  might  be  intrusted  with  the  daily  ob- 
servations, which  are  easy  to  record  ;  and  the  in- 
structions adopted  f  by  the  committee  of  the  scien- 

*  Bulletin  of  the  Imperial  Observatory,  number  of  July  19, 1864. 
t  Bulletin  of  the  Imperial  Observatory,  number  of  August 
25,  1864,  and  following  numbers. 


AGRICULTURAL   METEOROLOGY.  311 

tific  association,  of  which  we  shall  mention  the 
organization  farther  on,  would  soon  enable  him 
to  foresee  and  preannounce,  in  most  cases,  the  ap- 
proach of  atmospheric  disturbances.  Intelligent 
property-owners,  in  associating  themselves  also 
with  these  investigations,  would  not  only  obtain  in- 
dications calculated  to  aid  rural  pursuits  :  "  They 
will  always  be  certain,"  says  M.  de  Gasparin, 
"  of  finding  a  pleasant  and  useful  occupation  in 
meteorological  observations ;  in  their  comparison 
with  those  of  other  places  and  other  times,  and, 
while  amusing  their  leisure  hours,  they  will  be 
paving  the  way  to  the  period  when  meteorology 
will  acquire  the  certainty  of  deduction  which  it 
now  lacks,  and  when  conjectures  relative  to  fu- 
ture phenomena  will  become  probabilities." 

Let  us  add  that  the  comparison  of  series  of 
observations  made  at  different  periods  may  indi- 
cate, according  to  the  just  remark  of  M.  Buys- 
Ballot,  whether  the  natural  condition  of  the  place 
has  undergone  changes,  in  consequence  of  the 
cultivation  of  the  ground,  or  the  clearing  away  of 
forests,  the  drying  up  of  lakes,  arms  of  the  sea,  or 
marshes,  or  by  the  replanting  of  woods.  These 
indications  could  not,  undoubtedly,  acquire  a 
scientific  value,  excepting  by  the  lapse  of  time,  but 
they  would  be  infinitely  precious  to  us,  should 


312         METEORS   AND  METEORIC   PHENOMENA. 

they  go  to  confirm  the  influence  that  man  may 
exercise  over  the  character  of  climate  by  a  wise 
management  of  the  domain  confided  to  him. 

ASSOCIATION    FOB    THE    ADVANCEMENT    OF    METEOR- 
OLOGY. 

The  Meteorological  Society  of  France,  in  pub- 
lishing since  1849  a  yearly  Annuavre,  or  Calendar, 
intended  to  comprise  all  the  experiments  and  ob- 
servations which  had  been  but  little  known  until 
that  time,  and,  to  stimulate  fresh  researches,  has 
powerfully  contributed  to  the  progress  of  the 
studies  relating  to  a  knowledge  of  the  atmosphere 
and  of  the  phenomena  taking  place  in  it.  Under 
the  auspices  of  this  society,  M.  Eenou,  one  of  its 
members,  has  recently  commenced  a  course  of  me- 
teorology in  the  grand  amphitheatre  of  the  School 
of  Medicine.  This  course,  in  showing  the  impor- 
tance of  the  new  science,  accessible  as  it  is  to  all 
ranges  of  intellect,  will  give  a  new  impulse  to  the 
useful  research  and  to  the  interesting  observations 
that  it  invites  one  to  pursue. 

The  zealous  director  of  the  Journal  of  Prac- 
tical Agriculture,  M.  Barral,  has  brought  about 
the  formation  of  a  meteorological  net-work  based 
upon  the  free  cooperation  of  the  farmers,  and  it, 
in  permitting  the  monthly  publication  of  notes 


ADVANCEMENT   OF   METEOROLOGY.  313 

on  the  condition  of  the  crops,  at  the  same  time 
furnishes  the  best  documents  we  have  on  the  cli- 
matology of  France. 

Finally,  an  important  society  for  the  advance- 
ment of  astronomy  and  meteorology  has  recently 
been  established  under  the  presidency  of  M.  le 
Terrier.  The  following  extract  from  the  min- 
utes of  the  first  general  sitting,  which  took  place 
on  the  3d  of  June,  1864,  will  make  known  its 
object : 

"  Astronomy  and  meteorology  are  making 
rapid  progress  in  the  Old  as  well  as  in  the  New 
World,  thanks  to  the  cooperation  of  governments, 
individual  action,  and  powerful  associations ;  nu- 
merous establishments  have  been  founded,  and 
great  works  accomplished,  under  this  triple  im- 
pulsion. 

"  The  French  Government  stands  in  the  first 
rank  of  those  that  give  a  liberal  and  fruitful  sup- 
port to  science.  The  cities  of  Toulouse,  and  Mar- 
seilles are  erecting  observatories,  on  their  own 
behalf,  and  the  Chamber  of  Commerce  of  Toulon 
has  founded  a  yearly  prize  for  meteorological  ob- 
servations at  sea. 

u  The  Association  for  the  Advancement  of 
Astronomy  and  Meteorology  has  for  its  object  the 


314         METEORS  AND   METEORIC   PHENOMENA. 

completion  of  the  means  of  action  at  the  disposal 
of  France."  * 

After  this  exposition,  presented  to  the  meeting 
by  M.  le  Verrier,  the  committee  intrusted  with 
the  first  propositions  relative  to  meteorology,  rep- 
resented by  M.  Renou,  made  a  report,  of  which 
we  reproduce  the  principal  passages : 

"  Meteorology  is  one  of  the  sciences  that  were 
cultivated  in  the  earliest  times.  The  diversity  of 
climates  on  the  surface  of  the  globe ;  the  changes 
that  daily  take  place  in  the  state  of  the  heavens ; 
in  the  degree  of  movement,  heat,  and  dampness 
of  the  atmosphere ;  and,  above  all,  those  great  com- 
motions of  the  air  that  disturb  the  surface  of  the 
earth  and  the  sea,  concern  our  safety  and  comfort 
too  nearly  not  to  have  been  interesting  to  man- 
kind at  all  times. 

"  It  belonged,  however,  to  our  day,  in  which 
Science  advances  at  so  rapid  a  pace,  and  has  at 
her  disposal  so  many  resources  hitherto  unknown, 
to  give  meteorology  a  prolific  impulse  by  extend- 
ing her  investigations  over  the  whole  surface  of 
the  globe,  and  associating  individual  efforts  by 
the  rapid  intercommunication  of  results  obtained, 

*  This  association  counts  more  than  two  thousand  members, 
among  whom  are  a  great  many  ladies.  An  assessment  of  ten 
francs  per  annum  is  levied. 


ADVANCEMENT  OF  METEOROLOGY.  315 

"  The  services  rendered  to  navigation  by 
Maury,  and  by  those  who  have  striven  to  walk  in 
his  footsteps,  show  that  meteorology  has  entered 
its  true  path.  There  can  no  longer  be  any  doubt 
that,  by  combined  researches  carried  on  persever- 
ingly,  upon  a  scale  growing  continually  broader 
and  more  comprehensive,  it  must  attain  a  knowl- 
edge of  laws,  as  yet  unknown,  that  govern  the 
motions  of  the  atmosphere,  and  thus  at  last  give 
us  the  key  of  what  we  call  the  caprices  of  the 
weather. 

"  The  committee  was  struck  with  the  impor- 
tance of  the  position  already  given  to  meteorology 
by  the  initiative  of  France,  by  the  efforts  of  all  the 
nations  of  Europe,  and  by  the  eager  cooperation 
of  all  the  managing  boards  of  the  telegraphic  lines 
of  France  and  different  countries." 

After  having  made  known  the  great  interna- 
tional meteorological  service  of  which  the  Im- 
perial Observatory  of  Paris  is,  at  present,  the 
centre,  M.  Renou  adds : 

"  An  association  of  this  kind  is  incontestably 
a  fact  of  great  value,  and  the  end  at  which  it  aims 
is  most  important,  since  it  embraces  the  preven- 
tion of  those  disasters  that  annually  cost  the  lives 
of  thousands  of  men,  and  the  loss  of  millions  of 
property." 


316         METEOES   AND   METEORIC   PHENOMENA. 

M.  Renou  then  took  up  the  question  of  estab- 
lishing prizes,  for  meteorological  investigations,  to 
be  founded  by  the  society.  These  prizes,  three 
in  number,  are  to  be  bestowed  upon  the  authors 
of  the  best  treatises  on  the  general  movements  of 
the  atmosphere ;  the  best  observations  at  sea ;  and 
the  best  series  of  observations  made  at  places  but 
little  known.  Since  then,  two  new  prizes  have 
been  instituted,  to  be  given  to  the  authors  of  the 
two  best  treatises  relative  to  the  application  of 
meteorology  to  agricultural  questions. 

A  chart  summing  up  the  service  of  nautical 
meteorology,  the  centre  of  which  is  at  Paris,  has 
been  distributed  to  the  members  of  the  associa- 
tion. This  service,  by  which  warnings  of  bad 
weather  are  communicated,  now  extends  to  all  the 
coasts  of  the  Baltic  Sea,  to  that  of  the  North  Sea,  to 
the  French  coasts  of  the  Channel  and  the  Ocean, 
to  the  coasts  of  Portugal  and  Spain,  to  the  French 
coasts  of  the  Mediterranean,  to  those  of  Italy,  of 
Sicily,  of  the  Adriatic,  as  far  as  Albania,  and, 
finally,  to  the  Russian  coasts  of  the  Black  Sea. 

At  the  first  session  above  noted,  the  associa- 
tion voted  an  appropriation  applicable  to  the  con- 
struction of  a  large  telescope,  to  be  put  up  in  one 
of  the  large  cities  of  Southern  France. 

The  links  that  unite  astronomy,  meteorology, 


ADVANCEMENT   OF   METEOROLOGY.  317 

and  the  physical  constitution  of  the  globe,  were 
treated  with  great  elevation  of  views  by  Father 
Secchi,  the  director  of  the  observatory  at  Rome, 
in  a  series  of  memoranda  relative  to  the  connec- 
tion observed  between  the  variations  of  the  at- 
mosphere and  those  of  the  magnetism  of  the  earth. 
M.  Quetelet  also,  in  his  fine  treatise  on  periodic 
phenomena,  handled  those  topics  with  ability. 
The  latter  savant  very  correctly  said :  "  Astron- 
omy, and  particularly  the  observation  of  the  two 
great  luminaries  that  strike  our  gaze  the  most, 
may  be  considered  as  including  the  origin  of  all 
the  phenomena  that  deserve  to  engage  our  studi- 
ous attention." 

Arago,  in  his  "  Popular  Astronomy,"  has  also 
pointed  out  the  beauties  of  the  connection  that  the 
observation  of  cosmic  and  terrestrial  phenomena 
reveals  to  us : 

"  The  various  phenomena  of  the  starry  vault 
and  of  meteorology,  even  when  they  appear  by 
their  fickleness  to  baffle  all  the  perspicacity  of 
men,  at  length  are  seen,  after  profound  study,  to 
be  linked  together  in  sublime  coordination." 

M.  Renou,  in  his  memoranda  on  the  periodi- 
cal return  of  heavy  winters,  has  grouped  together 
the  important  facts  that  seem  to  prove  that  the 
period  of  the  principal  meteorological  phenomena 


318         METEORS   AND   METEORIC   PHENOMENA. 

is  associated  with  the  periods  of  the  shooting- 
stars,  the  solar  spots,  and  the  oscillations  of  the 
magnetic  needle.  These  relations,  although  as 
yet  chiefly  based  upon  conjecture,  as  M.  Renou 
remarks,  must  nevertheless  be  our  guide  in  seek- 
ing out  the  great  laws  that  govern  the  organi- 
zation of  worlds. 

It  is,  above  all,  by  the  knowledge  of  these  laws, 
by  the  admiration  that  they  imperatively  call  for 
in  us,  that  it  becomes  possible  for  us  to  conceive 
of  the  beneficent  action  of  the  Creative  Power ; 
to  rise  to  the  idea  of  Infinite  Wisdom,  and  to 
taste  the  ineffable  peace  of  that  religious  feeling 
which  Leibnitz  expressed  so  well  when  he  said, 
"  It  is  no  trivial  thing  to  be  content  with  God  and 
the  universe." 


NOTES. 

INSTRUMENTS   OF  OBSERVATION. 


The  Barometer. —The  Thermometer. — The  Hygrometer.— The  Plu- 
viometer, or  Udometer. 


THE   BAEOMETEE. 

AN  upright  tube  of  glass,  of  about  85  centimetres  (3-J- 
inches)  in  length,  filled  with  mercury,  and  standing  in  a 
cistern,  or  basin,  also  full  of  the  same  metal,  constitutes  a 
barometer.  The  atmospheric  pressure  is  measured  by  the 
difference  of  levels  established  between  the  tube  and  the 
receptacle.  Various  processes,  more  or  less  exact,  have 
been  employed  to  determine  this  difference. 

When  no  very  great  precision  is  required,  a  large  recep- 
tacle is  used,  and  no  attention  is  paid  to  the  variations  in 
the  level  of  the  mercury  that  it  contains.  Sometimes  it  is 
considered  sufficient  to  make  the  scale  movable,  so  as  to 
bring  the  zero  of  its  subdivisions  to  the  exterior  level.  In 
the  siphon  barometer,  the  tube  curved  near  the  foot  forms 
two  unequal  limbs,  the  larger  of  which  is  closed  and  the 
other  open.  It  requires  two  observations. 

Fortin's  barometer,  by  which  it  is  possible  to  take  more 
accurate  observations,  has  the  special  advantage  of  being 
very  portable,  but  it  is  dear.  It  is  distinguished  from  the 
rest  by  the  circumstance  that  the  level  of  the  mercury 


320  NOTES. 

in  the  receptacle  can  always  be  adjusted  with  much  pre- 
cision to  the  zero  of  the  fixed  scale.  When  the  observation 
is  carefully  made,  the  height  can  be  attained  within  the 
twentieth  part  of  a  millimetre. 

Taking  the  precaution  to  compare  it  from  time  to  time 
with  a  mercury  barometer,  the  aneroid  barometer  may  be 
employed  in  meteorological  observations.  It  is  composed 
of  a  flexible  brass  tube,  and  is  bent  over  in  a  ring  that 
nearly  closes.  A  vacuum  is  made  beforehand,  and,  when 
the  atmospheric  pressure  increases  or  diminishes,  the  ring 
closes  or  opens,  and  this  movement  communicates  itself  to 
a  needle  that  marks  the  pressure  on  an  index. 

THE   THEEMOMETEE. 

The  mercury  thermometer  is  usually  employed  in  the 
observatories,  and  alcohol  does  not  become  necessary  ex- 
cept in  regions  where  the  cold  congeals  the  metal/  The 
liquid,  the  dilation  of  which  is  to  be  observed,  is  enclosed 
in  a  capillary  glass  tube,  soldered  to  a  cylindrical  or  spher- 
ical reservoir  of  the  same  material.  The  scale  is  graduated 
on  the  tube  itself,  or  upon  a  ruled  register  running  parallel 
to  it,  the  former  arrangement  being  the  best.  The  temper- 
ature of  melting  ice  has  been  taken  as  the  zero  of  this 
scale,  and  for  the  second  fixed  point,  represented  by  one 
hundred  degrees,  the  boiling  temperature  of  distilled  water 
in  a  metallic  receptacle,  the  atmospheric  pressure  being 
CT.75. 

In  order  to  ascertain  the  lowest  temperature  at  night 
and  the  highest  by  day,  special  instruments  are  substituted 
for  ordinary  thermometers.  Kutherford's  thermometer,  a 
minima,  is  the  simplest.  Placed  horizontally,  or  very 


mSTRTJMENTS   OF   OBSERVATION.  321 

slightly  inclined  to  the  side  opposite  the  reservoir,  it  con- 
tains alcohol  and  an  index  formed  hy  a  small  enamelled 
cylinder.  When  the  liquid  contracts,  this  body  is  carried 
with  it,  by  an  adhesive  effect,  up  to  the  point  that  cor- 
responds with  the  maximum  of  contraction.  The  temper- 
ature then  rising,  the  alcohol  dilates  and  passes  between 
the  inner  surface  of  the  tube  and  the  index,  without  dis- 
placing the  later. 

The  thermometer,  a  maxima,  of  the  same  inventor,  is 
also  arranged  with  mercury,  and  encloses  a  cylindrical 
index  of  iron.  The  instrument  being  placed  horizontally, 
and  the  fluid  dilating,  the  cylinder  is  pushed  before  it.  It 
remains  in  its  place  when  the  fluid  contracts,  because  there 
is  no  adhesion  between  mercury  and  iron.  A  magnet  is 
employed  to  reestablish  contact. 

The  commission  of  the  Scientific  Association  recom- 
mends the  thermometer,  a  maxima,  of  Messrs.  Negretti  and 
Zambra,  London  opticians.  It  is  a  mercury  thermometer, 
the  stem  of  which  is  choked  near  the  reservoir  by  a 
point  of  glass  which  is  soldered  to  it  inside.  The  mercury 
passes  this  obstacle  during  the  increase  of  temperature; 
but  when  it  is  descending,  the  thermometer  being  hori- 
zontal, the  column  of  mercury  is  separated  at  the  ob- 
structed point,  and  remains  in  its  place.  "When  the  obser- 
vation has  been  made,  it  is  sufficient  to  set  the  instrument 
upright  again  and  give  it  a  slight  shake,  in  order  to  make 
the  mercury  fall  back  into  the  reservoir. 

THE   HYGROMETER. 

When  we  speak  of  the  hygrometrio  condition  of  the 
atmosphere,  we  mean  the  relation  between  the  actual 


322  NOTES. 

quantity  of  watery  vapor  that  it  contains,  and  the  quan- 
tity that  it  would  contain  were  it  saturated,  the  temper- 
ature being  the  same  in  both  cases.  In  order  to  get  at  this 
relation,  instruments  termed  hygrometers  are  used.  They 
are  constructed  in  accordance  with  the  property  that 
bodies  have  of  becoming  elongated  by  moisture  and  con- 
tracted by  dryness.  Another  mode  of  observing  humidity 
is  by  the  psychrometer,  which  consists  in  simultaneously 
watching  two  thermometers,  the  one  dry  and  the  other 
with  its  reservoir  kept  constantly  wet. 

Saussure's  hygrometer  is  formed  of  a  hair  previously 
freed  of  grease.  Its  variations  of  length  are  communicated 
to  a  needle  moving  on  a  marked  dial.  Zero  is  fixed  at 
the  point  where  the  needle  stops  when  the  air  is  com- 
pletely dry,  and  one  hundred  degrees  at  the  point  it 
touches  when  the  air  is  saturated  with  watery  vapor. 
The  indications  of  this  instrument  are  not  proportional 
to  the  hygrometric  condition  of  the  air.  In  order  to  ob- 
tain the  latter,  the  tables  prepared  by  Gay-Lussac  must  be 
used. 

In  the  psychrometer  method,  the  evaporation  that  takes 
place  on  the  wet  reservoir  causes  a  decrease  of  temper- 
ature, from  which,  by  means  of  a  simple  calculation,  may 
be  deduced  the  elastic  force  of  the  vapor,  and,  conse- 
quently, the  degree  of  moisture  existing  in  the  air. 

THE   PLTJVIOMETEE,    OB   UDOMETEE. 

The  pluviometer,  or  udometer,  is  an  instrument  that 
serves  to  measure  the  quantity  of  rain  that  falls  during  a 
given  time  in  a  given  place.  Different  forms  might  be  de- 
scribed, but  one  of  the  most  simple  is  represented  in  the 


INSTRUMENTS   OF   OBSERVATION.  323 

Magasin  Pittoresque,  vol.  xxiv.,  1856,  p.  192.  Consider- 
able improvements  were  proposed  some  years  ago  by  M. 
Herve-Mangon.  The  pluviometer  of  the  marine  depot,  of 
which  we  give  an  illustration,  is  composed  of  a  double 
reservoir  of  tin,  with  inclined  planes,  movable  upon  a  cen- 
tral axis,  to  serve  as  an  overfall.  The  rain-water  being  re- 
ceived in  a  wide  funnel,  the  surface  of  which  is  determined 
according  to  each  apparatus,  passes  by  a  conduit  into  a 
second  reservoir  A,  above  the  receptacle  B.  The  water 
issues  from  it  by  a  small  orifice,  and  falls  upon  one  of  the 
inclined  planes  of  the  receptacle.  When  a  certain  amount 


PLUVIOMETER. 


has  flowed  off,  according  to  the  condition  of  the  apparatus, 
the  receptacle  tips  back,  strikes  against  a  copper  stem  0  0, 
and  the  water  runs  off  into  a  lateral  reservoir  D  D. 

This  tipping  or  oscillating  movement  recurs  thus  every 


324:  NOTES. 

time  that  a  sufficient  weight  of  water  has  fallen.  The  prin- 
cipal merit  of  the  apparatus  is,  that  it  registers  of  itself  the 
volume  of  water  received :  for  this  purpose  there  is  joined 
to  the  horizontal  axis  E  a  needle  F,  the  extremity  of  which 
plunges  into  G,  a  small  tank  of  mercury,  every  time  that  the 
oscillating  movement  takes  place. 

During  this  very  brief  period  an  electric  current  is  es- 
tablished :  it  is  produced  by  two  wires,  H  and  K,  one  of 
which,  K,  communicates  with  L,  the  foot  of  the  tank,  and 
the  other  with  the  mercury  G.  By  means  of  a  special 
piece  of  mechanism,  the  current  itself  marks  a  point,  each 
time  that  the  tipping  occurs,  upon  a  roll  of  paper  that 
passes  on  with  a  uniform  motion.  A  glance  at  the  sheet 
will  then  let  us  know  how  much  water  fell  at  any  given 
time  in  the  day. 


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From  April,  1861,  to  April,  1865. 
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"The  fact  that  I  became  a  member  of  General  Grant's  personal  staff, 
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have  since  remained  with  him,  is  the  voucher  that  I  offer  for  the  correctness 
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my  own  personal  observation,  or  has  been  told  me  by  the  General  of  the  Army, 
or  one  of  his  important  officers,  or  unless  I  know  it  from  official  papers.  When 
I  deviate  from  this  rule,  I  make  the  deviation  known. 

"The  correspondence,  telegraphic  and  written,  of  the  headquarters  of 
the  armies,  is  accessible  to  me.  I  have  also  been  allowed  to  examine  all 
papors  under  the  control  of  the  War  Department ;  and,  as  many  of  the  rebel 
archives  are  now  in  the  possession  of  the  Government,  I  have  seen  the  original 
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otherwise,  the  source  is  named. 

"  Generals  Sherman,  Sheridan,  Ord,  and  Wilson,  and  the  officers  of  General 
Grant's  staff,  as  well  as  Admiral  Porter,  have  afforded  me  much  valuable 
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desired.  The  Honorable  Edwin  M.  Stanton  has  also  furnished  me  with 
information  which  1  could  not  otherwise  have  obtained. 

"The  present  volume  brings  my  narrative  down  to  the  period  when 
General  Grant  was  made  Lieutenant-General,  and  assumed  command  of  all 
the  national  armies.  It  refers  to  scenes  and  events,  many  of  which  I  did 
not  personally  witness,  as  I  first  reported  to  him,  in  person,  in  February,  1864. 
His  private  as  well  as  official  correspondence,  and  daily  conversation  lor  years 
•with  himself  and  the  officers  who  accompanied  him  in  his  earlier  campaigns, 
are  my  principal  authority.  I  have  his  permission  now  to  make  known  what- 
ever 1  have  learned  from  these  various  sources. 

"  My  opinions,  however,  have  not  been  submitted  to  General  Grant.  For 
them  I  alone  am  responsible.  But,  those  opinions  are  based  exclusively  on 
the  facts  presented  to  the  reader,  and,  unless  supported  by  the  evidence  I 
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Idiomatically.'' 


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of  the  problem,  How  to  obtain  facility  in 

speaking  foreign  languages  grammatically,  without 

using  THE  GEAMMAE  in  the  first  stage.    It  adopts  and 

systematizes  that  process  by  which  many  couriers 

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.  "We  know  that  there  are  some  who 
have  given  Mr.  Prendergast's  plan  a  trial, 
and  discovered  that  in  a  very  few  weeks 
its  results  had  surpassed  all  their  antici- 
pations."—-2%^  Record. 

"  The  Mastery  System  gives,  in  our 
opinion,  all  the  advantages  of  Ollen- 
dorff's,  and  is  free  from  its  defects.  .  .  . 
To  gain  a  thorough  command  of  the 
common  phrases  which  the  majority  use 
exclusively  and  all  men  chiefly,  is  the 
goal  at  which  the  mastery  system  aims, 
and  we  think  that  goal  can  be  reached 
by  its  means  more  easily  and  in  a 


shorter  time  than  by  any  method  yet 
made  known."— Norfolk  News. 

"Mr..Prendergast'8  scheme  has  the 
merit  of  simplicity,  being  nothing  more 
nor  less  than  a  deduction  from  the  nat- 
ural method  pursued  by  children,  aided 
by  the  reason  or  intelligence  which  chil- 
dren do  not  possess,  but  which  belongs 
to  adults."—  Greenock  Advertiser. 

" .  .  .  .  En  un  mot,  c'est  le  systeme 
le  plus  pratique  que  la  philologie  ait 
produit  pour  1'enseignement  dea  lan- 
gues  Strangeres."  —  L  ''Impartial  de 
Boulogne. 


New  York:   D.  APPLETON  &  CO. 


Works  published  by  1).  Appleton  db  Co. 


HEAT, 

CONSIDERED  AS  A  MODE  OF  MOTION, 

Being  a  Course  of  Twelve  Lectures   delivered   before  the 
Royal  Institution  of  Great  Britain. 

BY  JOHN  TTNDALL,  P.  E.  8., 

PBOFESSOB    OF   NATURAL    PHILOSOPHY  IN    THE    EOYAL    INSTITtTTION— AUTHOB    OF    TH* 

"GLAOIEBS  or  THB  ALPS,"  ETC. 
With  One  Hundred  Illustrations.     8vo,  480  pages.    Price,  $2.00. 


From  the  American  Journal  of  Science.— With  all  the  skill  which  has 
made  Faraday  the  master  of  experimental  science  in  Great  Britain,  Professor  Tyndall 
enjoys  the  advantage  of  a  superior  general  culture,  and  is  thus  enabled  to  set  forth  his 
philosophy  with  all  the  graces  of  eloquence  and  the  finish  of  superior  diction.  With  a 
simplicity,  and  absence  of  technicalities,  which  render  his  explanations  lucid  to  un- 
scientific minds,  and  at  the  same  time  a  thoroughness  and  originality  by  which  he  in- 
structs the  most  learned,  he  unfolds  all  the  modern  philosophy  of  heat  His  work  takes 
rank  at  once  as  a  classic  upon  the  subject. 

New  York  Times.— Professor  Tyndall's  course  of  lectures  on  heat  is  one  of  the 
most  beautiful  illustrations  of  a  mode  of  handling  scientific  subjects,  which  is  com- 
paratively new,  and  which  promises  the  best  results,  both  to  science  and  to  literature 
generally ;  we  mean  the  treatment  of  subjects  in  a  style  at  once  profound  and  popu- 
lar. The  title  of  Professor  Tyndall's  work  indicates  the  theory  of  heat  held  by  him, 
and  indeed  the  only  one  now  held  by  scientific  men— it  is  a  mode  of  motion. 

Boston  Journal.— He  exhibits  the  curious  and  beautiful  workings  of  nature  in 
a  most  delightful  manner.  Before  the  reader  particles  of  water  lock  themselves  or  fly 
asunder  with  a  movement  regulated  like  a  dance.  They  form  themselves  into  liquid 
flowers  with  fine  serrated  petals,  or  into  rosettes  of  frozen  gauze;  they  bound  upward 
in  boiling  fountains,  or  creep  slowly  onward  in  stupendous  glaciers.  Flames  burst  into 
music  and  sing,  or  cease  to  sing,  as  the  experimenter  pleases,  and  metals  paint  them- 
selves upon  a  screen  in  dazzling  hues  as  the  painter  touches  his  canvas. 

New  York  Tribune.— The  most  original  and  important  contribution  that  has 
yet  been  made  to  the  theory  and  literature  of  thermotics. 

Scientific  American.— The  work  is  written  in  a  charming  style,  and  is  the 
most  valuable  contribution  to  scientific  literature  that  bis  been  published  in  many 
years.  It  is  the  most  popular  exposition  of  the  dynamical  theory  of  heat  that  has  yet 
appeared.  The  old  material  theory  of  heat  may  be  said  to  be  defunct 

Louisville  Democrat.— This  is  one  of  the  most  delightful  scientific  works  we 
htve  ever  met  The  lectures  are  so  full  of  life  and  spirit  that  we  can  almost  imagine 
the  lecturer  before  us,  and  see  his  brilliant  experiments  in  every  stage  of  their  progress. 
The  theory  is  so  carefully  and  thoroughly  explained  that  no  one  can  fail  to  understand 
It.  Such  books  as  these  create  a  love  for  science. 

Independent.— Professor  Tyndall's  expositions  and  experiments  are  remarkably 
thoughtful,  ingenious,  clear,  and  convincing ;  portions  of  the  book  have  almost  th- 
in terest  of  a  romance,  so  startling  are  the  descriptions  and  elucidations. 


THE 

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